CN-122001327-A - Resonator of epitaxial growth packaging structure based on zirconium doped diamond

CN122001327ACN 122001327 ACN122001327 ACN 122001327ACN-122001327-A

Abstract

The application discloses a resonator of an epitaxial growth packaging structure based on zirconium doped diamond, and relates to the field of micro-electromechanical system resonators. The piezoelectric ceramic comprises a substrate layer, a piezoelectric functional layer, an electrode layer and an epitaxial growth packaging layer, wherein the substrate layer, the piezoelectric functional layer, the electrode layer and the epitaxial growth packaging layer are sequentially arranged from bottom to top, the piezoelectric functional layer is a piezoelectric film prepared by adopting a zirconium doped diamond material, the electrode layer adopts a composite electrode structure design, the bottom layer is an adhesive layer, the upper layer is a conductive layer, the epitaxial growth packaging layer adopts a diamond material, and the epitaxial growth packaging layer and the piezoelectric functional layer are integrally formed through an epitaxial growth process. The method is used for solving the technical defects that the existing resonator is insufficient in high-frequency working performance, the Q value and the low power consumption requirement are difficult to cooperate and consider, the structural reliability is poor due to the traditional packaging technology, the frequency stability is easy to attenuate in the long-term use process, and the like.

Inventors

LIU SHA
ZHANG SHENGKANG
XU HUIHUI
WANG CHAO
WANG JIANBING
Zhao Shengshuang
LI YING
LI BOHONG
YU HONGLONG

Assignees

北京无线电计量测试研究所

Dates

Publication Date: 20260508
Application Date: 20251226

Claims (10)

1. The resonator of the epitaxial growth packaging structure based on the zirconium doped diamond is characterized by comprising a substrate layer, a piezoelectric functional layer, an electrode layer and an epitaxial growth packaging layer, wherein: The substrate layer, the piezoelectric functional layer, the electrode layer and the epitaxial growth packaging layer are sequentially arranged from bottom to top; The piezoelectric functional layer is a piezoelectric film prepared from zirconium doped diamond material; The electrode layer adopts a composite electrode structure design, the bottom layer is an adhesive layer, and the upper layer is a conductive layer; The epitaxial growth packaging layer is made of diamond material and is integrally formed with the piezoelectric functional layer through an epitaxial growth process.
2. The resonator according to claim 1, characterized in that the piezoelectric film of the piezoelectric functional layer is prepared by vapor deposition process and the lattice defect is eliminated by annealing treatment.
3. The resonator according to claim 1, characterized in that the epitaxially grown encapsulation layer forms a hermetic encapsulation cavity integrally formed with the piezoelectric functional layer during encapsulation.
4. The resonator according to claim 1, characterized in that the piezoelectric functional layer and the electrode layer constitute a suspended resonant unit, the support and the energy isolation being achieved by a substrate shallow trench structure.
5. The resonator according to claim 1, characterized in that the substrate layer is a monocrystalline silicon substrate, designed with a specific crystal orientation for matching the growth requirements of the piezoelectric functional layer.
6. The resonator according to claim 1, characterized in that the electrode pattern of the electrode layer is of an interdigital design.
7. The resonator according to claim 1, characterized in that the epitaxially grown encapsulation layer comprises a reserved interconnection window extending through the epitaxially grown encapsulation layer exposing the electrode layer for electrical connection of the electrode layer to an external control circuit.
8. The resonator according to claim 7, characterized in that the electrical connection of the external control circuit to the electrode layer is achieved using micro-nano interconnection technology.
9. The resonator of claim 7, wherein the external control circuit comprises a resonance detection module, a parasitic suppression module, and a power management module, wherein: the resonance detection module adopts a low-noise and broadband operational amplifier and is used for collecting frequency signals of the resonance unit; The parasitic suppression module is used for suppressing parasitic signals of a high frequency band by selecting components with low temperature drift and low parasitic parameters to form a filter circuit; the power management module adopts a low-power-consumption voltage stabilizing device and is internally provided with a power supply filter circuit for stabilizing output power supply voltage.
10. A process for preparing a resonator for a zirconium-doped diamond based epitaxial growth package according to any of claims 1-9, comprising: the substrate layer pretreatment, namely removing greasy dirt and impurities on the surface of the substrate through cleaning, plasma etching and surface activation processes in sequence to form a basic structure suitable for supporting the piezoelectric functional layer; Preparing a diamond substrate film by a vapor deposition process, introducing zirconium atoms by a sputtering process synchronously, uniformly doping zirconium elements into diamond lattices, and eliminating lattice defects generated in the deposition process by annealing treatment in an inert gas atmosphere; the electrode layer forming, namely defining an interdigital electrode pattern and the outline of a resonance unit by adopting a high-precision photoetching process, realizing the precise forming of the resonance unit by adopting a dry etching process to form a suspension structure, and finally removing residual photoresist by adopting a photoresist removing process; depositing an electrode layer, namely sequentially depositing an adhesion layer and a conductive layer of the composite electrode by adopting a sputtering process, and carrying out low-temperature annealing treatment after the deposition is finished; The epitaxial growth packaging layer is formed by defining a packaging area on the surface of the electrode layer through a photoetching process and reserving an interconnection window, and then continuing a vapor deposition process to grow a diamond epitaxial layer in the packaging area to form a sealed packaging cavity integrally formed with the piezoelectric functional layer; And finally, removing the mask outside the packaging area, and carrying out fine processing on the interconnection window.

Description

Resonator of epitaxial growth packaging structure based on zirconium doped diamond Technical Field The application relates to the technical field of micro-electromechanical systems (MEMS) resonators, in particular to a resonator with an epitaxial growth packaging structure based on zirconium doped diamond. Background Along with the evolution of the fifth generation mobile communication technology (5G) to the sixth generation mobile communication technology (6G), the large-scale landing of the autopilot technology and the high-precision development of the miniature medical electronic equipment, the resonator is used as a core frequency control and signal processing element in the electronic equipment, the performance of the resonator directly determines the running precision, the response speed and the cruising ability of the terminal equipment, the current industry puts forward the quadruple core technical requirements of high frequency, low power consumption, microminiaturization and high reliability for the resonator, and the following key technical defects still exist in the prior art, so that the application requirements are difficult to meet: the traditional quartz crystal resonator is limited in high-frequency resonance performance, the upper limit of the working frequency is difficult to promote due to the characteristics of materials and the processing technology, the crystal structure of the traditional MEMS resonator based on common piezoelectric materials is easy to be influenced under a high-frequency scene, the resonance frequency cannot be adapted to the high-frequency band requirement required by 6G communication, and the electromechanical coupling efficiency is obviously reduced under the high-frequency working condition, so that the signal transmission efficiency is reduced; The quality factor (Q value) is contrary to the low power consumption requirement that the traditional piezoelectric material adopted by the existing resonator has low overall quality factor (Q value), and under the high-frequency working condition, the dielectric loss and the mechanical loss of the material are aggravated, so that the energy loss of the resonator is higher, and the low power consumption use requirement of the miniature electronic equipment is difficult to meet; The packaging process has multiple technical bottlenecks that the main flow packaging scheme of the existing resonator comprises wafer-level bonding packaging (such as anodic bonding and glass-silicon bonding), metal shell packaging and plastic packaging processes, and has obvious defects that (1) interface stress is caused by thermal stress and mechanical stress generated in the packaging process, so that lattice distortion of a resonant unit is easy to occur, Q value attenuation is caused, (2) vacuum maintenance capability is insufficient, the air tightness of the traditional resonator is difficult to guarantee for a long time, the vacuum environment in a packaging cavity is deteriorated after the traditional resonator is used for a long time, gas damping loss is increased, and (3) material compatibility is poor, the thermal expansion characteristics of a packaging layer and a piezoelectric functional layer are not matched, and interface stripping phenomenon is easy to occur under an extreme temperature environment. The frequency stability is difficult to ensure, in complex electromagnetic environment, temperature circulation and long-term use scenes, the air tightness of the packaging layer of the existing resonator is easy to attenuate, the interface between the functional layer and the packaging layer is easy to undergo oxidation reaction, and meanwhile, the thermal effect of residual gas in the packaging cavity is aggravated, so that the frequency drift of the resonator is obvious, and the signal synchronization precision of a communication module, the ranging accuracy of radar equipment and the detection precision of medical electronic equipment are seriously affected. In summary, the existing resonators have technical bottlenecks in terms of high-frequency working performance, balance of Q value and power consumption, reliability of packaging structure, frequency stability and the like, and cannot meet the severe application demands of high-end fields such as 6G communication, automatic driving, miniature medical electronics and the like. Disclosure of Invention The application aims to provide a resonator based on an epitaxial growth packaging structure of zirconium-doped diamond, which is used for solving the technical defects that the existing resonator is insufficient in high-frequency working performance, difficult to cooperate with the Q value and low power consumption requirement, poor in structural reliability caused by the traditional packaging technology, easy to attenuate in frequency stability in the long-term use process and the like. In order to achieve the above purpose, the application adopts the following technical scheme