CPC H10N 30/076 (2023.02) [H03H 3/02 (2013.01); H10N 30/053 (2023.02); H10N 30/06 (2023.02); H10N 30/85 (2023.02); Y10T 29/42 (2015.01); Y10T 29/49005 (2015.01)] | 8 Claims |
1. A method of forming an acoustic resonator device, the method comprising:
sputtering onto a first surface of a substrate to provide a piezoelectric thin film comprising AlN, AlScN, AlCrN, HfMgAlN, or ZrMgAlN on the first surface of the substrate while the first surface of the substrate is at a temperature in a range between 350 degrees Centigrade to 850 degrees Centigrade;
processing a second surface of the substrate that is opposite the first surface of the substrate to provide an exposed surface of the piezoelectric thin film from beneath the second surface of the substrate, wherein the exposed surface of the piezoelectric thin film comprises a first crystalline quality portion of the piezoelectric thin film;
removing a portion of the exposed surface of the piezoelectric thin film to access a second crystalline quality portion of the piezoelectric thin film that is covered by the first crystalline quality portion of the piezoelectric thin film, wherein the second crystalline quality portion of the piezoelectric thin film has a crystallinity of less than 1.0 degree at Full Width Half Maximum (FWHM) to 10 arcseconds at FWHM measured using X-ray diffraction (XRD); and
processing the second crystalline quality portion of the piezoelectric thin film to provide an acoustic resonator device on the second crystalline quality portion of the piezoelectric thin film.
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