CN-122003092-A - Preparation method of driving induction device based on piezoelectric film

CN122003092ACN 122003092 ACN122003092 ACN 122003092ACN-122003092-A

Abstract

The invention discloses a preparation method of a driving induction device based on a piezoelectric film, which relates to the technical field of semiconductors and comprises the steps of simultaneously etching a first electrode layer, an induction/driving layer, a second electrode layer and a vibration functional layer, in comparison with the prior art that the multilayer films are etched respectively, the overlay error is not needed to be considered in the whole etching process. In addition, since the etching is performed through the whole device layer at the same time, the selection ratio of etching of different materials is not required to be considered, and a physical bombardment mode such as IBE can be selected to obtain the optimal etching verticality. The performance of the driving induction device manufactured by the method is more close to the ideal design performance, and larger redundancy is reserved for process errors.

Inventors

ZHANG SHENGBING
JIANG NAN

Assignees

安徽华鑫微纳集成电路有限公司

Dates

Publication Date: 20260508
Application Date: 20260203

Claims (10)

1. The preparation method of the driving induction device based on the piezoelectric film is characterized by comprising the following steps of: preparing a vibration functional layer, and bonding the vibration functional layer with the substrate layer; sequentially forming a second electrode layer, an induction/driving layer and a first electrode layer on the vibration functional layer; patterning the first electrode layer, the induction/driving layer and the second electrode layer in sequence; etching the first electrode layer, the induction/driving layer, the second electrode layer and the vibration functional layer simultaneously to form a displacement/vibration structure; And bonding a third wafer above the first electrode layer, and forming an external electrode on the third dome part.
2. The method for manufacturing a piezoelectric thin film-based driving induction device according to claim 1, wherein the manufacturing of the vibration functional layer comprises the steps of: And carrying out doping treatment on at least one side surface of the first wafer, and annealing the doped region.
3. The method of claim 1, wherein if frequency trimming is required for the driving sensor, the substrate layer is made of monocrystalline silicon material to transmit laser light, and one or more of the following modes are adopted: depositing a frequency trimming layer on the bottom of the vibration functional layer before bonding, or The adjustment of the vibration structure quality is completed by burning the frequency trimming layer through the substrate layer by laser to achieve the purpose of frequency adjustment, or And a laser blocking layer is additionally deposited on one side surface of the substrate layer to control the trimming position of laser.
4. The method for manufacturing a piezoelectric thin film based driving sensing device according to claim 1, wherein the second electrode layer, the sensing/driving layer, and the first electrode layer are sequentially formed on the vibration functional layer, specifically comprising the steps of: Doping treatment is carried out on the top of the vibration functional layer, and the doping concentration is controlled to form a second electrode layer with a conductive function, or a metal material is deposited on the top of the vibration functional layer to form the second electrode layer; depositing a piezoelectric material on the second electrode layer to form an induction/driving layer; a metal material is deposited on the sense/drive layer to form a first electrode layer.
5. The method for manufacturing a piezoelectric thin film based driving sensing device according to claim 1, wherein the patterning process is performed on the first electrode layer, the sensing/driving layer, and the second electrode layer in this order, comprising: patterning the first electrode layer to form a conductive pattern; Patterning the induction/driving layer to form a piezoelectric material boundary; and carrying out patterning treatment on the second electrode layer to form electric field distribution matched with the first electrode layer.
6. The method for manufacturing a piezoelectric thin film based driving induction device according to claim 1, wherein the bonding of the third wafer over the first electrode layer comprises the steps of: Forming an isolation layer on the first electrode layer, and forming a first bonding/conducting layer on the isolation layer, wherein the first bonding/conducting layer is made of a first eutectic material; forming a TSV structure on the third wafer; Oxidizing the bottom of the third wafer to form a first oxide layer, and forming a second bonding/conducting layer on the first oxide layer, wherein the second bonding/conducting layer adopts a second eutectic material; Bonding the first bonding/conductive layer with the second bonding/conductive layer.
7. The method of manufacturing a piezoelectric thin film based driving induction device according to claim 6, wherein the forming of the isolation layer on the first electrode layer and the forming of the first bonding/conductive layer on the isolation layer are performed before the forming of the displacement/vibration structure, comprising the steps of: Depositing silicon oxide on the surface of the first electrode layer, and performing graphical treatment; and depositing the first eutectic material on the surface of the isolation layer, and performing graphical treatment.
8. The method of manufacturing a piezoelectric thin film based driving induction device according to claim 6, wherein the forming of the TSV structure on the third wafer comprises the steps of: deep reactive ion etching is carried out on one side surface of the third wafer to form a shallow cavity and a deep groove; depositing silicon oxide and polysilicon on the same side surface of the third wafer, so that the deep groove is filled with the silicon oxide and the polysilicon; carrying out back etching and CMP planarization treatment on the surface of the same side of the third wafer; And forming a gas-absorbing layer in the shallow cavity.
9. The method for manufacturing a piezoelectric thin film based driving induction device according to claim 1, wherein the forming of the external electrode at the third dome portion comprises the steps of: thinning the top of the third wafer, depositing a second oxide layer, and patterning the second oxide layer; Depositing conductive metal, and patterning the conductive metal to form an external electrode; And depositing silicon oxide to form a protective layer, and patterning the protective layer to expose the external electrode.
10. A piezoelectric film based driving sensing device manufactured by the manufacturing method according to any one of claims 1 to 9.

Description

Preparation method of driving induction device based on piezoelectric film Technical Field The invention relates to the technical field of semiconductors, in particular to a preparation method of a driving induction device based on a piezoelectric film. Background The structure of the driving induction device is shown in fig. 1, wherein the device layer sequentially comprises a vibration functional layer 2, a second electrode layer 5, an induction/driving layer 3 and a first electrode layer 4 from bottom to top, the electrode layers are made of conductive materials, the induction/driving layer is a piezoelectric film, and the vibration functional layer is made of monocrystalline silicon materials. In addition to the patterning of the layers required to perform their functions, the device layers are etched to form displacement/vibration structures 9. Conventional processes perform corresponding etches according to different properties of each layer of material, such as ICP (Inductively Coupled Plasma ), RIE (reaction ionetching, reactive ion etching), and the like. Because the displacement/vibration structure 9 penetrates through the device layer, additional compensation needs to be made for the alignment precision in the process and the perpendicularity of each layer, and therefore a larger minimum line width needs to be adopted, so that the processing error resistance of the displacement/vibration structure is poor and the overall yield is low. Disclosure of Invention In order to overcome the defects in the prior art, the invention provides a preparation method of a driving induction device based on a piezoelectric film, which solves the problems that in the prior art, the alignment precision and the perpendicularity of each layer of a displacement/vibration structure are required to be additionally compensated, so that a larger minimum line width is required to be adopted, and the processing error resistance is poor and the overall yield is low. In order to achieve the above purpose, the present invention adopts the following technical scheme, including: a preparation method of a driving induction device based on a piezoelectric film comprises the following steps: preparing a vibration functional layer, and bonding the vibration functional layer with the substrate layer; sequentially forming a second electrode layer, an induction/driving layer and a first electrode layer on the vibration functional layer; patterning the first electrode layer, the induction/driving layer and the second electrode layer in sequence; etching the first electrode layer, the induction/driving layer, the second electrode layer and the vibration functional layer simultaneously to form a displacement/vibration structure; And bonding a third wafer above the first electrode layer, and forming an external electrode on the third dome part. Preferably, the preparing of the vibration functional layer includes the steps of: And carrying out doping treatment on at least one side surface of the first wafer, and annealing the doped region. Preferably, if frequency trimming is required for the driving sensing device, the substrate layer is made of monocrystalline silicon material to transmit laser light, and one or more of the following modes are adopted: depositing a frequency trimming layer on the bottom of the vibration functional layer before bonding, or The adjustment of the vibration structure quality is completed by burning the frequency trimming layer through the substrate layer by laser to achieve the purpose of frequency adjustment, or And a laser blocking layer is additionally deposited on one side surface of the substrate layer to control the trimming position of laser. Preferably, the forming the second electrode layer, the sensing/driving layer, and the first electrode layer on the vibration functional layer in sequence specifically includes the following steps: Doping treatment is carried out on the top of the vibration functional layer, and the doping concentration is controlled to form a second electrode layer with a conductive function, or a metal material is deposited on the top of the vibration functional layer to form the second electrode layer; depositing a piezoelectric material on the second electrode layer to form an induction/driving layer; a metal material is deposited on the sense/drive layer to form a first electrode layer. Preferably, the patterning process is performed on the first electrode layer, the sensing/driving layer, and the second electrode layer sequentially, including: patterning the first electrode layer to form a conductive pattern; Patterning the induction/driving layer to form a piezoelectric material boundary; and carrying out patterning treatment on the second electrode layer to form electric field distribution matched with the first electrode layer. Preferably, the bonding the third wafer over the first electrode layer includes the steps of: Forming an isolation layer on the first electrode lay