The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 09, 2024
Filed:
Dec. 09, 2020
Murata Manufacturing Co., Ltd, Kyoto, JP;
Patrick Turner, San Bruno, CA (US);
Ryo Wakabayashi, Santa Clara, CA (US);
MURATA MANUFACTURING CO., LTD, Nagaokakyo, JP;
Abstract
An acoustic resonator is fabricated by etching a recess in a silicon thermal oxide (TOX) upper layer of a silicon substrate and filling the recess with sacrificial polysilicon. A surface of the silicon TOX layer and the sacrificial polysilicon-filled recess are planarized. A back surface of a single-crystal piezoelectric plate is bonded to the planarized surface of the silicon TOX layer. Openings are formed through the piezoelectric plate and an interdigital transducer (IDT) is formed on a front surface of the piezoelectric plate such that interleaved fingers of the IDT are disposed over the sacrificial polysilicon-filled recess. The sacrificial polysilicon is removed from the recess to form a cavity such that a portion of the piezoelectric plate forms a diaphragm spanning the cavity and the interleaved fingers of the IDT are disposed on the diaphragm.