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:
Jun. 11, 2019
Filed:
Aug. 04, 2017
Texas Instruments Incorporated, Dallas, TX (US);
Neng Jiang, Plano, TX (US);
Xin Li, Carrollton, TX (US);
Joel Soman, Dallas, TX (US);
Thomas Warren Lassiter, Garland, TX (US);
Mary Alyssa Drummond Roby, Plano, TX (US);
YungShan Chang, Plano, TX (US);
TEXAS INSTRUMENTS INCORPORATED, Dallas, TX (US);
Abstract
A microelectronic device containing a piezoelectric thin film element is formed by oxidizing a top surface of a piezoelectric layer with an oxygen plasma, and subsequently forming an etch mask containing photoresist on the oxidized top surface. The etch mask is conditioned with an oven bake followed by a UV bake. The piezoelectric layer is etched using a three step process: a first step includes a wet etch of an aqueous solution of about 5% NHF, about 1.2% HF, and about 18% HCl, maintaining a ratio of the HCl to the HF of about 15.0, which removes a majority of the piezoelectric layer. A second step includes an agitated rinse. A third step includes a short etch in the aqueous solution of NHF, HF, and HCl.