Title:
HIGH-BANDWIDTH SILICON BACK FACE ETCHING TYPE FILM BULK ACOUSTIC RESONATOR, AND PREPARATION METHOD THEREFOR
Document Type and Number:
WIPO Patent Application WO/2023/143005
Kind Code:
A1
Abstract:
Provided in the present invention are a high-bandwidth silicon back face etching type film bulk acoustic resonator, and a preparation method therefor. The bulk acoustic resonator sequentially comprises a substrate, a dense oxide film, a bottom electrode, a composite piezoelectric film and a top electrode from bottom to top; the top electrode, the composite piezoelectric film and the bottom electrode form a sandwich structure; the middle part of the substrate is of a hollow structure so as to form an air-metal interface at the lower part of the bottom electrode; and a masking layer is further arranged at the bottom of the substrate. The preparation method comprises: preparing dense oxide films on two sides of a substrate; removing one of the dense oxide films to serve as a back etching face; preparing a masking layer on the back etching face, and performing photoetching patterning processing on the masking layer according to the size of a hollow structure, so as to form a back etching window; preparing a bottom electrode on the face of the substrate having the dense oxide film; preparing a composite piezoelectric film on the bottom electrode; preparing a top electrode on the composite piezoelectric film; and etching off a substrate structure of a corresponding area of the back etching window, so as to form a hollow structure.
Inventors:
LI GUOQIANG (CN)
Application Number:
PCT/CN2023/071329
Publication Date:
August 03, 2023
Filing Date:
January 09, 2023
Export Citation:
Assignee:
HEYUAN AIFO LIGHT COMMUNICATION TECH CO LTD (CN)
International Classes:
H03H9/02; H03H3/02
Foreign References:
| CN114584096A | 2022-06-03 | |||
| CN114362711A | 2022-04-15 | |||
| CN114531126A | 2022-05-24 | |||
| CN105897211A | 2016-08-24 | |||
| CN111697937A | 2020-09-22 |
Attorney, Agent or Firm:
JIAQUAN IP LAW (CN)
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