MEMS magnetoelectric antenna based on in-chip bias magnetic field and preparation method and application thereof

Abstract

The invention discloses an MEMS magnetoelectric antenna based on an on-chip bias magnetic field and a preparation method and application thereof, and belongs to the technical field of magnetoelectric antennas. In order to solve the problems that in the prior art, an MEMS magnetoelectric antenna cannot provide a bias magnetic field in a chip to achieve miniaturization, and the bonding temperature needed for preparation is high, the MEMS magnetoelectric antenna sequentially comprises a bottom substrate, an antenna base, an antenna end cap and a top sealing cover from bottom to top; an MEMS bias coil cavity is arranged among the bottom substrate, the antenna base, the antenna end cap and the top sealing cover; an antenna sensitive structure is arranged between the antenna substrate and the antenna end cap. The micro-sized MEMS solenoid coil is integrated in the MEMS magnetoelectric antenna chip, and a bias magnetic field is provided for the antenna, so that the antenna has optimal performance and small volume; in addition, vacuum packaging of the MEMS magnetoelectric antenna is carried out in a low-temperature environment lower than the Curie temperature of the magnetoelectric composite material, the performance of the magnetoelectric composite material is not affected, and air damping is remarkably reduced.

Description

Technical Field

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

[0002] Magnetoelectric antennas achieve mutual conversion between magnetic field and electric field through magnetoelectric coupling effect, which can break through the constraints of antenna size and electromagnetic wavelength. With its unique working principle and superior performance, it has become a current research hotspot. Especially in the field of low-frequency communications, magnetoelectric antennas can reduce the size of traditional antennas by 2 to 3 orders of magnitude.

[0003] The sensitive structure of the MEMS magnetoelectric antenna is composed of a piezoelectric film and a magnetostrictive film. When it senses an external alternating magnetic field, it outputs an induced voltage due to the magnetoelectric coupling effect. However, there is a nonlinear relationship between the output strain and output displacement of the magnetostrictive film and the external DC magnetic field. Only by providing an appropriate bias magnetic field for the prepared magnetoelectric coupling film can the antenna achieve optimal 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 fully utilize the miniaturization advantages of MEMS technology and improve the performance of the MEMS magnetoelectric antenna. 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 the 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 precisely control, and it is impossible to ensure that the antenna is always in the optimal bias state. By integrating the MEMS micro-nano coil on the chip, the internal magnetic field strength can be flexibly adjusted by precisely controlling the current. This method does not require changing the structure or preparation process of the MEMS micro-nano coil to meet the working requirements of the MEMS magnetoelectric antenna under different optimal bias magnetic fields.

[0005] In MEMS magnetoelectric antennas, magnetostrictive materials use a length-direction (L-direction) polarization mode to improve the output response of the sensitive structure. Therefore, the required bias magnetic field must be parallel to the substrate plane. MEMS micro-nano coils are of two types: planar coils and solenoid coils. On-chip planar coils not only occupy a large area and have a low inductance density, but can only provide a bias magnetic field in the thickness direction (T direction) for the magnetostrictive film, which cannot meet the working requirements of MEMS magnetoelectric antennas. 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] The invention patent with the publication number CN103674997B proposes a low-field nuclear magnetic resonance probe based on a printed circuit board solenoid coil, with a PCB substrate as a substrate, 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 arranged on the upper surface of the PCB substrate, and a group of third leads arranged side by side, a fourth lead and a fifth lead are arranged on the lower surface of the PCB substrate, which has the advantages of simple manufacture, low cost, short cycle and batch production. However, the line width of the printed circuit board is limited by the process, and the sensitive structure size of the MEMS magnetoelectric antenna is larger than that of the micron-level MEMS magnetoelectric antenna, which cannot meet the requirements of antenna miniaturization. The invention patent application document with the publication number CN104076057A proposes a probe based on the integration of a gallium solenoid microcoil and a glass microfluidic channel and a preparation method thereof. The temperature parameter of the bonding process used in the preparation method is 500~600 degrees Celsius, which exceeds the Curie temperature of the magnetoelectric composite material and will cause material modification. The metal winding is cast with gallium, but 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] In view of the above-mentioned problems, the present invention aims to provide a MEMS magnetoelectric antenna based on an on-chip bias magnetic field, a preparation method and an application thereof. By integrating a micron-scale MEMS solenoid coil in the MEMS magnetoelectric antenna chip, a bias magnetic field is provided for the antenna, so that it has optimal performance and a tiny size. In addition, the MEMS magnetoelectric 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, thereby improving the quality factor of the sensitive structure.

[0008] In order to achieve the above object, the technical solution adopted by the present invention is as follows: On the one hand, the present invention provides a MEMS magnetoelectric antenna based on an on-chip bias magnetic field, wherein the MEMS magnetoelectric antenna comprises, from bottom to top, a bottom substrate, an antenna base, an antenna end cap, and a top cover; A MEMS bias coil cavity is provided between the bottom substrate, the antenna base, the antenna end cap and the top cover; An antenna sensitive structure is arranged between the antenna substrate and the antenna end cap.

[0009] Furthermore, a plurality of long strip-shaped bottom electrode cavities are provided on the top surface of the bottom substrate, and the ends of the two outermost bottom electrode cavities that are away from each other are vertically extended and provided with MEMS bias coil pads; Two rows of first through hole cavity arrays corresponding to the ends of the bottom electrode cavity are provided on the antenna substrate; The antenna end cap is provided with two rows of second through hole cavity arrays corresponding to the first through hole cavity array; A plurality of top electrode cavities are formed on the top cover, and each top electrode cavity corresponds to and connects two second through hole cavity arrays that are arranged in the same order in the front-to-back direction; The bottom electrode cavity, the first through-hole cavity array, the second through-hole cavity array and the top electrode cavity together constitute a MEMS bias coil cavity.

[0010] Furthermore, an antenna lower side cavity is opened at the top center of the antenna substrate, and the antenna sensitive structure is located at the top of the antenna lower side cavity; An antenna upper side cavity for accommodating the antenna sensitive structure is opened at the bottom center of the antenna end cap.

[0011] Furthermore, the antenna sensitive structure includes a first electrode, a piezoelectric layer, a second electrode and a magnetostrictive layer in order from bottom to top, and one side of the second electrode is tilted downward and connected to the first electrode.

[0012] Furthermore, the first electrode is extended to both sides and led out to both sides of the upper surface of the antenna substrate, and antenna sensitive structure electrode pads are provided at both ends.

[0013] Further, the filling material of the MEMS bias coil cavity includes any one of gold, copper, silver or nickel.

[0014] On the other hand, the present invention also provides a method for preparing a MEMS magnetoelectric antenna based on an on-chip bias magnetic field as described above, comprising the following steps: Step 1: dry-etching the bottom substrate, antenna base, antenna end cap and top cover to prepare a MEMS bias coil cavity; Step 2: Fill the MEMS bias coil cavity with electrodes through a metal electroplating process and perform polishing; Step 3: Perform silicon-silicon bonding on the bottom substrate and the antenna base, and on the antenna end cap and the top cover respectively; Step 4: Prepare the antenna upper side cavity on the lower surface of the antenna end cap by dry etching; Step 5: preparing an antenna sensitive structure on the upper surface of the bonded antenna substrate; Step 6: Align and bond the antenna substrate prepared with the antenna sensitive structure to the antenna end cap.

[0015] Furthermore, the specific operation of step 6 includes the following steps: Step 601: electroplating a gold layer on the lower surface of the antenna end cap to prepare an intermediate layer electrode that overlaps with the vertical projection of the second through hole cavity array; Step S602: Spin-coat BCB glue on the lower surface of the antenna end cap to remove the BCB glue remaining on the middle layer electrode; Step S603: pre-baking the lower surface of the antenna end cap at 105° C. to remove the solvent and volatile substances and partially solidify the BCB glue; 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; Step S605: heat the bonding interface to 250° C. and keep it at this temperature for 1 hour, then slowly cool it down to room temperature.

[0016] On the other hand, the present invention also provides the application of the MEMS magnetoelectric antenna based on the on-chip bias magnetic field as described above in a medical implantable device.

[0017] The beneficial effects of the present invention are as follows: compared with the prior art, the present invention has the following improvements: 1. The present invention proposes a MEMS magnetoelectric antenna based on an on-chip bias magnetic field. By integrating a micron-sized MEMS solenoid coil in a MEMS magnetoelectric antenna chip, a bias magnetic field is provided for the antenna, making it have the best performance and a small size. 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.

[0018] 2. The present invention proposes a method for preparing a MEMS magnetoelectric antenna based on an on-chip bias magnetic field. The solenoid coil that provides the bias magnetic field is manufactured through the MEMS process, 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 and improves the quality factor of the sensitive structure. The entire process design is reasonable and has good repeatability and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a structural breakdown diagram of the MEMS magnetoelectric antenna based on the on-chip bias magnetic field in the present invention.

[0020] Figure 2 It is a structural cross-sectional view of the antenna substrate and the antenna sensitive structure in the present invention.

[0021] Figure 3 It is a schematic diagram of the overall structure of the MEMS bias coil and antenna sensitive structure in the present invention.

[0022] Figure 4 It is a schematic diagram of the operation of preparing the first electrode on the upper surface of the antenna substrate in the present invention.

[0023] Figure 5 It is a schematic diagram of the operation of preparing a piezoelectric layer on the upper surface of the antenna substrate in the present invention.

[0024] Figure 6It is a schematic diagram of the operation of preparing the second electrode on the upper surface of the antenna substrate in the present invention.

[0025] Figure 7 It is a schematic diagram of the operation of preparing a magnetostrictive layer on the upper surface of an antenna substrate in the present invention.

[0026] Among them: 1. bottom substrate; 11. bottom electrode cavity; 111. MEMS bias coil pad; 2. antenna base; 21. first through-hole cavity array; 22. antenna lower cavity; 3. antenna end cap; 31. second through-hole cavity array; 32. antenna upper cavity; 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 DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments. Embodiment 1

[0028] Embodiment 1 provides a MEMS magnetoelectric antenna based on an on-chip bias magnetic field, as shown in the attached Figure 1-3 The MEMS magnetoelectric antenna based on the on-chip bias magnetic field comprises a bottom substrate 1, an antenna base 2, an antenna end cap 3 and a top cover 4 from bottom to top.

[0029] 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 distributed at equal intervals; the bottom electrode cavities 11 are in a long strip structure, and the ends of the two outermost bottom electrode cavities 11 that are away from each other are vertically extended and provided with MEMS bias coil pads 111.

[0030] The antenna substrate 2 is provided with two rows of first through-hole cavity arrays 21, the number of the first through-hole cavity arrays 21 in each row is one less than the number 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-to-back direction. The antenna substrate 2 is provided with an antenna lower side cavity 22 at the top center, and the antenna lower side cavity 22 is provided with an antenna sensitive structure 5 at the top.

[0031] The antenna end cap 3 is provided with two rows of second through hole cavity arrays 31, which correspond one-to-one with the first through hole cavity array 21, and their projections in the vertical direction completely overlap; the bottom center of the antenna end cap 3 is provided with an antenna upper cavity 32, which corresponds to the antenna lower cavity 22.

[0032] A plurality of top electrode cavities 41 are provided at the bottom of the top cover 4, and the top electrode cavities 41 are tilted, and each top electrode cavity 41 corresponds to and connects two second through-hole cavity arrays 31 arranged in the same order in the front-to-back direction, that is, the leftmost top electrode cavity 41 connects the leftmost second through-hole cavity array 31 in the back row and the leftmost second through-hole cavity array 31 in the front row, and so on.

[0033] In the present invention, the bottom electrode cavity 11, the first through-hole cavity array 21, the second through-hole cavity array 31 and the top electrode cavity 41 together constitute a MEMS bias coil cavity.

[0034] Preferably, the MEMS bias coil cavity may be filled with gold, copper, silver or nickel. In this embodiment, gold is selected as the filling material.

[0035] Furthermore, the antenna sensitive structure 5 is located on the top of the antenna substrate 2, and the antenna sensitive structure 5 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 tilted downward and connected to the first electrode 51; the first electrode 51 is extended to both sides and 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 support structures.

[0036] Preferably, in the present invention, the bottom substrate 1, the antenna base 2, the antenna end cap 3 and the top cover 4 are all made of double-sided polished high-resistance silicon (resistivity>10000Ω / cm), and the bottom substrate 1, the antenna base 2, the antenna end cap 3 and the top cover 4 have the same width dimensions, and the length dimensions are the longest for the bottom substrate 1, the second longest for the antenna base, and the equal and shortest for the antenna end cap 3 and the top cover 4. The bottom substrate 1, the antenna base 2, the antenna end cap 3 and the top cover 4 are bonded to form an integral structure.

[0037] The working principle of the MEMS magnetoelectric antenna based on the on-chip bias magnetic field in actual use in the present invention is: (a) testing the resonant frequency of the antenna sensitive structure 5 through the antenna sensitive structure electrode pad 511; (b) A constant signal with the same resonant frequency as the antenna sensitive structure 5 is applied externally, and a uniform and changing DC magnetic field is applied along the length (L) direction of the antenna sensitive structure 5 through an external coil, and the output signal of the antenna sensitive structure 5 is detected through the antenna sensitive structure electrode pad 511. When the output signal is the strongest, the strength of the DC magnetic field applied at this time is the corresponding optimal bias magnetic field. B ; (c) The MEMS bias coil (the MEMS bias coil cavity is filled with metal gold to form the MEMS bias coil) provides the best bias magnetic field according to the following formula: B Required input current : In the formula, is the vacuum permeability, n is the turns density of the coil; (d) By applying a corresponding input current to the MEMS bias coil pad 111 I , so that a uniform optimal DC bias magnetic field is generated inside the MEMS bias coil along the length direction of the antenna sensitive structure 5 B , so that the antenna sensitive structure 5 is in the best working state. Embodiment 2

[0038] Embodiment 2 provides a method for preparing a MEMS magnetoelectric antenna based on an on-chip bias magnetic field as described in Embodiment 1, which specifically includes the following steps: Step 1: Preparation of MEMS bias coil cavity; Specifically, the upper surface of the bottom substrate 1 is dry-etched to produce a bottom electrode cavity 11 including a MEMS bias coil pad 111; the antenna base 2 is dry-etched to produce a first through-hole cavity array 21; the antenna end cap 3 is dry-etched to produce a second through-hole cavity array 31; the lower surface of the top cover 4 is dry-etched to produce a top electrode cavity 41; the bottom electrode cavity 11, the first through-hole cavity array 21, the second through-hole cavity array 31 and the top electrode cavity 41 together constitute a MEMS bias coil cavity.

[0039] Step 2: Fill the MEMS bias coil cavity with electrodes through a metal electroplating process and perform polishing; Specifically, in the present invention, gold is used as the electrode material, the bottom electrode cavity 11 is subjected to metal electroplating to form a bottom electrode, and the upper surface of the bottom substrate 1 is polished; the first through-hole cavity array 21 is subjected to metal electroplating to form a first through-hole electrode array, and the upper and lower surfaces of the antenna base 2 are polished; the second through-hole cavity array 31 is subjected to metal electroplating to form a second through-hole electrode array, and the upper and lower surfaces of the antenna end cap 3 are polished; the top electrode cavity 41 is subjected to metal electroplating to form a top electrode, and the lower surface of the top cover 4 is polished.

[0040] Step 3: Perform silicon-silicon bonding on the upper surface of the bottom substrate 1 and the lower surface of the antenna base 2, and on the upper surface of the antenna end cap 3 and the lower surface of the top cover 4, respectively. After bonding, the bottom electrode and the first through-hole electrode array are connected in ohmic contact, and after bonding, the second through-hole electrode array and the top electrode are connected in ohmic contact.

[0041] Step 4: Prepare the antenna upper side 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, as shown in the attached Figure 4-7 As shown, the specific steps include: Step 501: Photolithography is performed on the upper surface of the antenna substrate 2, and 100 nm of gold is sputtered and peeled off, and a first electrode 51 including an antenna sensitive structure electrode pad 511 is formed on the upper surface of the antenna substrate 2, as shown in the attached Figure 4 As shown; Step 502: Sputter a 2 μm thick ZnO piezoelectric film on the upper surface of the antenna substrate 2, and perform photolithography and wet etching with dilute hydrochloric acid (HCl) to obtain a piezoelectric layer 52, as shown in the attached figure. Figure 5 As shown; Step 503: After photolithography on the upper surface of the piezoelectric layer 52, a 100 nm gold layer is evaporated, and the second electrode 53 is obtained by peeling. Figure 6 As shown; Step 504: After continuing to perform photolithography on the upper surface of the second electrode 53, a 2 μm thick FeGaB magnetostrictive film is sputtered, and the magnetostrictive layer 54 is obtained by peeling off. Figure 7 As shown; Step 505: Prepare a patterned photoresist as a protective layer on the upper surface of the antenna substrate 2, and use XeF2 to etch the antenna substrate 2 under the antenna sensitive structure 5 to obtain the antenna lower side cavity 22, and finally form the attached Figure 2 The complete antenna substrate 2 and antenna sensitive structure 5 are shown.

[0042] Step 6: Align and bond the upper surface of the antenna substrate 2 on which the antenna sensitive structure 5 is prepared with the lower surface of the antenna end cap 3; specifically, the following steps are included: Step 601: electroplating 6 micron thick gold on the lower surface of the antenna end cap 3, using a patterning process to obtain an intermediate layer electrode that overlaps with the vertical projection of the second through hole cavity array 31; Step 602: Spin-coat a 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 BCB glue remaining on the middle layer electrode; Step 603: pre-bake the lower surface of the antenna end cap 3 at 105° C. for 5 minutes to remove the solvent and volatile substances therein and partially solidify the BCB glue; 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 through-hole electrode array is aligned with the intermediate layer electrode, and apply a pressure of 1 MPa to make the bonding interface in close contact; Step 605: Heat the bonding interface to 250° C. and keep it at this temperature for 1 hour, then slowly cool it down to room temperature.

[0043] It should be noted that in step 505, the reaction between XeF2 and the silicon substrate during the etching process is expressed as follows: The gas generated after the reaction is exhausted through the vacuum system in step 604 .

[0044] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached 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 comprises, from bottom to top, a bottom substrate (1), an antenna base (2), an antenna end cap (3) and a top cover (4); A MEMS bias coil cavity is provided between the bottom substrate (1), the antenna base (2), the antenna end cap (3) and the top cover (4); An antenna sensitive structure (5) is provided between the antenna base (2) and the antenna end cap (3); The top surface of the bottom substrate (1) is provided with a plurality of long strip-shaped bottom electrode cavities (11), and ends of the two outermost bottom electrode cavities (11) that are away from each other are vertically extended and provided with MEMS bias coil pads (111); Two rows of first through hole cavity arrays (21) corresponding to the ends of the bottom electrode cavity (11) are provided on the antenna substrate (2); The antenna end cap (3) is provided with two rows of second through hole cavity arrays (31) corresponding to the first through hole cavity array (21); A plurality of top electrode cavities (41) are provided on the top cover (4), and each top electrode cavity (41) corresponds to and connects two second through-hole cavity arrays (31) that are arranged in the same order in the front-to-back direction; The bottom electrode cavity (11), the first through-hole cavity array (21), the second through-hole cavity array (31) and the top electrode cavity (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, characterized in that: An antenna lower cavity (22) is provided at the center of the top of the antenna base (2), and the antenna sensitive structure (5) is located at the top of the antenna lower cavity (22); An antenna upper side 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, characterized in that: The antenna sensitive structure (5) comprises, from bottom to top, a first electrode (51), a piezoelectric layer (52), a second electrode (53) and a magnetostrictive layer (54); one side of the second electrode (53) is tilted 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) is extended to both sides and 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, characterized in that: The filling material of the MEMS bias coil cavity includes any one of gold, copper, silver or nickel.

6. A method for preparing a MEMS magnetoelectric antenna based on an on-chip bias magnetic field as claimed in any one of claims 2 to 5, characterized in that: The following steps are included: Step 1: dry-etching the bottom substrate (1), the antenna base (2), the antenna end cap (3) and the top cover (4) to prepare a MEMS bias coil cavity; Step 2: Fill the MEMS bias coil cavity with electrodes through a metal electroplating process and perform polishing; Step 3: performing silicon-silicon bonding on the bottom substrate (1) and the antenna base (2), and on the antenna end cap (3) and the top cover (4); Step 4: preparing an antenna upper side cavity (32) on the lower surface of the antenna end cap (3) by dry etching; Step 5: preparing an antenna sensitive structure (5) on the upper surface of the bonded antenna substrate (2); Step 6: Align and bond the antenna substrate (2) prepared with the antenna sensitive structure (5) and the antenna end cap (3).

7. The method for preparing a MEMS magnetoelectric antenna based on an on-chip bias magnetic field according to claim 6, characterized in that: The specific operation of step 6 includes the following steps: Step 601: electroplating a gold layer on the lower surface of the antenna end cap (3) to prepare an intermediate layer electrode that overlaps with the projection of the second through hole cavity array (31) in the vertical direction; Step S602: Spin-coating BCB glue on the lower surface of the antenna end cap (3) to remove the BCB glue remaining on the middle layer electrode; Step S603: pre-baking the lower surface of the antenna end cap (3) at 105° C. to remove the solvent and volatile substances and partially solidify 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 at this temperature for 1 hour, then slowly cool it down to room temperature.

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

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