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CN-114337584-B - Resonator and method of forming the same

CN114337584BCN 114337584 BCN114337584 BCN 114337584BCN-114337584-B

Abstract

A method for forming a resonator includes providing a piezoelectric stack structure including a first region and a second region surrounding the first region, the piezoelectric stack structure having a first side and a second side opposite the first side, forming a first dielectric layer on the first side of the piezoelectric stack structure, providing a first substrate having a top doped region on top of the first substrate, bonding the first dielectric layer to the top of the first substrate, forming a second dielectric layer on the second side of the piezoelectric stack structure, etching the first dielectric layer, the piezoelectric stack structure, and the second dielectric layer of the second region to form a first opening and a second opening exposing the top doped region, and forming a first plug and a second plug in the first opening and the second opening, respectively. When the resonator works, the first plug is used for leading the static current of the rear section to the first substrate, the Schottky diode is broken down rapidly, and the static of the rear section is released, so that the electric performance of the resonator is improved.

Inventors

  • LI WEI
  • HUANG HE
  • LUO HAILONG

Assignees

  • 中芯集成电路（宁波）有限公司
  • 中芯集成电路（宁波）有限公司

Dates

Publication Date
20260421
Application Date
20200928
Priority Date
20200928

Claims (20)

  1. 1. A method of forming a resonator, comprising: providing a piezoelectric stack structure comprising a first region and a second region surrounding the first region, the piezoelectric stack structure having a first face and a second face opposite the first face; Forming a first dielectric layer on the first face of the piezoelectric stack structure; providing a first substrate, wherein the top of the first substrate is provided with a top doping region; Bonding the first dielectric layer to the top of the first substrate; After bonding the first dielectric layer and the top of the first substrate, forming a second dielectric layer on the second surface of the piezoelectric stack structure; Etching the first dielectric layer, the piezoelectric stack structure and the second dielectric layer of the second region to form a first opening and a second opening exposing the top doped region; and filling conductive materials in the first opening and the second opening to form a first plug and a second plug respectively.
  2. 2. The method of forming a resonator of claim 1, wherein in the step of providing a first substrate, the top doped region comprises a well region; The method of forming the resonator further includes providing a first substrate, bonding the first dielectric layer to a top portion of the first substrate, Forming a first doped region and a second doped region which are spaced apart from each other at the top of the well region, wherein the doping ions of the first doped region and the doping ions of the second doped region have different conductive types; In the step of forming the first opening and the second opening, the first opening exposes the first doped region, and the second opening exposes the second doped region.
  3. 3. The method of forming a resonator according to claim 1 or 2, wherein the top doped region is doped with P-type ions or N-type ions.
  4. 4. The method of forming a resonator according to claim 2, wherein in the step of forming the first doped region and the second doped region, the first doped region is doped with N-type ions and the second doped region is doped with P-type ions.
  5. 5. The method of forming a resonator of claim 2, wherein in the step of forming the first doped region and the second doped region, the first doped region and the second doped region are spaced apart by 3 microns to 1000 microns.
  6. 6. The method of forming a resonator of claim 2, wherein the step of forming first and second spaced apart doped regions on top of the well region comprises: forming a first shielding layer covering the well region, wherein the first shielding layer is provided with a first groove exposing part of the well region of the second region; doping first type ions in the well region exposed by the first shielding layer to form a first doped region; The method for forming the resonator further comprises the steps of removing the first shielding layer after the first doped region is formed; After the first shielding layer is removed, forming a second shielding layer covering the well region, wherein the second shielding layer is provided with a second groove exposing part of the well region of the second region; Doping second type ions in the well region exposed by the second shielding layer to form a second doped region; The method for forming the resonator further comprises the step of removing the second shielding layer after the second doping region is formed.
  7. 7. The method of forming a resonator according to claim 6, wherein an ion implantation process is used to dope ions in the well region exposed by the first shielding layer to form a first doped region; And doping ions in the well region exposed by the second shielding layer by adopting an ion implantation process to form a second doped region.
  8. 8. The method of forming a resonator according to claim 1 or 2, further comprising forming a first sacrificial layer on the piezoelectric stack in a first region before forming a first dielectric layer on the piezoelectric stack; Forming the first dielectric layer on the first sacrificial layer and the piezoelectric laminated structure exposed by the first sacrificial layer in the step of forming the first dielectric layer; the method for forming the resonator further comprises bonding the first dielectric layer and the top of the first substrate, and then forming a second sacrificial layer on the second surface of the piezoelectric laminated structure in the first region; The method for forming the resonator further comprises the step of removing the first sacrificial layer and the second sacrificial layer after the second dielectric layer is formed and before the first opening and the second opening are formed.
  9. 9. The method of forming a resonator of claim 8, wherein removing the first sacrificial layer and the second sacrificial layer comprises etching the second dielectric layer, the second sacrificial layer, and the piezoelectric stack in a first region to form a first release hole exposing the first sacrificial layer; removing the first sacrificial layer and the second sacrificial layer after forming the first release hole; In the step of forming the first release hole, the first dielectric layer of the first region is also etched to form a second release hole exposing the second sacrificial layer.
  10. 10. The method of forming a resonator of claim 1, further comprising forming an insulating layer on sidewalls of the first and second openings after forming the first and second openings and before filling the first and second openings with a conductive material.
  11. 11. The method of forming a resonator of claim 10 wherein the insulating layer comprises one or more of silicon oxide, silicon nitride, and silicon oxynitride.
  12. 12. The method of forming a resonator of claim 1, wherein the first dielectric layer, the piezoelectric stack structure, and the second dielectric layer of the second region are etched using a dry etching process to form a first opening and a second opening exposing the top doped region.
  13. 13. The method of forming a resonator according to claim 1 or 2, characterized in that the method of forming a resonator comprises: Providing a second substrate before providing the piezoelectric stack structure; In the step of providing a piezoelectric stack structure, forming the piezoelectric stack structure on the second substrate; the method for forming the resonator further comprises the step of removing the second substrate after bonding the first dielectric layer and the top of the first substrate.
  14. 14. A kind of resonator which is used for the resonance of the liquid crystal, characterized by comprising the following steps: A first substrate comprising a first region and a second region surrounding the first region, the top of the first substrate having a top doped region; A first dielectric layer on the first substrate; a piezoelectric stack structure on the first dielectric layer; a second dielectric layer on the piezoelectric stack; a first plug penetrating the second dielectric layer, the piezoelectric stack structure, and the first dielectric layer of the second region and contacting the first substrate; and the second plug penetrates through the second dielectric layer, the piezoelectric laminated structure and the first dielectric layer of the second area and is in contact with the first substrate, and the second plug is spaced from the first plug.
  15. 15. The resonator of claim 14, wherein the top doped region comprises a well region; the resonator also comprises a first doped region, a second doped region and a third doped region, wherein the first doped region is positioned at the top of the well region; the second doped region is positioned at the top of the well region, the first doped region and the second doped region are spaced, and the doping ions of the first doped region and the doping ions of the second doped region have different conductive types; the first plug is contacted with the top of the first doped region, and the second plug is contacted with the top of the second doped region.
  16. 16. A resonator as claimed in claim 14 or 15, wherein the top doped region is doped with P-type ions or N-type ions.
  17. 17. The resonator of claim 15, wherein the first doped region is doped with N-type ions and the second doped region is doped with P-type ions.
  18. 18. The resonator of claim 15, wherein the first doped region and the second doped region are spaced apart by 3 microns to 1000 microns.
  19. 19. The resonator of claim 14, further comprising a first cavity located between a top of the first dielectric layer and the piezoelectric stack; and the second cavity is positioned between the bottom of the second dielectric layer and the piezoelectric laminated structure.
  20. 20. The resonator of claim 14, further comprising an insulating layer between the first plug and the first dielectric layer, between the first plug and the piezoelectric stack, between the first plug and the second dielectric layer, between the second plug and the first dielectric layer, between the second plug and the piezoelectric stack, and between the second plug and the second dielectric layer.

Description

Resonator and method of forming the same Technical Field The present disclosure relates to semiconductor devices, and particularly to a resonator and a method for forming the same. Background With the development of mobile communication technology, the amount of mobile data transmission is rapidly increasing. Therefore, on the premise that the frequency resources are limited and as few mobile communication devices as possible should be used, the problem of increasing the transmission power of the wireless power transmission devices such as the wireless base station, the micro base station or the repeater is to be considered, and meanwhile, the requirement on the power of the filter in the front-end circuit of the mobile communication device is also higher and higher. At present, a high-power filter in equipment such as a wireless base station mainly comprises a cavity filter, the power of the cavity filter can reach hundreds of watts, and in addition, a medium filter is used in some equipment, and the average power of the medium filter can reach more than 5 watts. But both filters are large in size and difficult to integrate into the rf front-end chip. Currently, thin film bulk acoustic resonators (Film Bulk Acoustic Resonator, FBAR) based on semiconductor micromachining technology are capable of well overcoming the drawbacks of both filters. The FBAR has the advantages of high working frequency, high received power, high quality factor (Q value), small volume, favorable integration, good compatibility with a silicon wafer process, good reliability and the like. Disclosure of Invention The invention solves the problem of providing a resonator and a forming method thereof, and improves the performance of the resonator. In order to solve the problems, the invention provides a method for forming a resonator, which comprises the steps of providing a piezoelectric laminated structure, forming a first substrate, bonding a top doping area on the top of the first substrate, forming a second dielectric layer on the second surface of the piezoelectric laminated structure after bonding the top of the first dielectric layer and the top of the first substrate, etching the first dielectric layer, the piezoelectric laminated structure and the second dielectric layer of the second area to form a first opening and a second opening exposing the top doping area, filling conductive materials in the first opening and the second opening, and forming a first plug and a second plug respectively. Correspondingly, the invention further provides a resonator which comprises a first substrate, a first dielectric layer, a piezoelectric laminated structure, a second dielectric layer, a first plug, a second dielectric layer, a piezoelectric laminated structure and a first dielectric layer, wherein the first substrate comprises a first area and a second area surrounding the first area, the top of the first substrate is provided with a top doped area, the first dielectric layer is arranged on the first substrate, the piezoelectric laminated structure is arranged on the first dielectric layer, the second dielectric layer is arranged on the piezoelectric laminated structure, the first plug penetrates through the second dielectric layer, the piezoelectric laminated structure and the first dielectric layer of the second area and is in contact with the first substrate, and the second plug penetrates through the second dielectric layer, the piezoelectric laminated structure and the first dielectric layer of the second area and is in contact with the first substrate, and is spaced from the first plug. Compared with the prior art, the technical scheme of the invention has the following advantages: In the method for forming the resonator provided by the embodiment of the invention, the first dielectric layer, the piezoelectric lamination structure and the second dielectric layer of the second region are etched to form the first opening and the second opening exposing the top doping region, conductive materials are filled in the first opening and the second opening to form the first plug and the second plug respectively, the bottom ends of the first plug and the second plug are respectively contacted with the top doping region, the first plug and the second plug are made of metal, the top doping region is made of semiconductor material doped with ions, and the first plug and the top doping region, the second plug and the top doping region form the schottky diode. In the alternative, the top doped region formed on the top of the first substrate comprises a well region, a first doped region and a second doped region which are spaced apart are formed on the top of the well region, the doping ions of the first doped region and the doping ions of the second doped region are different in conductivity type, and in the step of forming the first opening and the second opening, the first opening exposes the first doped region, and the second opening exposes th