Methods for fabricating acoustic structure with inclined c-axis piezoelectric bulk and crystalline seed layers
AssigneeQorvo US, Inc.
InventorsKevin McCarron, John Belsick
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Abstract
Systems and methods for growing hexagonal crystal structure piezoelectric material with a c-axis that is tilted (e.g., 25 to 50 degrees) relative to normal of a face of a substrate are provided. A deposition system includes a linear sputtering apparatus, a translatable multi-aperture collimator, and a translatable substrate table arranged to hold multiple substrates, with the substrate table and/or the collimator being electrically biased to a nonzero potential. An enclosure includes first and second deposition stations each including a linear sputtering apparatus, a collimator, and a deposition aperture.
Claims17
A method for fabricating at least one bulk acoustic wave resonator structure, the method comprising:
- a first growth step including deposition of a crystalline seed layer over at least one resonator device complex, wherein each resonator device complex of the at least one resonator device complex includes a substrate and at least one first electrode structure arranged over at least a portion of the substrate, and wherein the first growth step is configured to yield at least 50% of the crystalline seed layer comprising a c-axis having an orientation distribution predominantly in a range of from 0 degrees to 35 degrees relative to normal of a face of the substrate;
- and
- a second growth step including deposition of a hexagonal crystal structure piezoelectric material bulk layer over the crystalline seed layer that is arranged over the at least one resonator device complex, and being configured to yield at least 50% of the hexagonal crystal structure piezoelectric material bulk layer comprising a c-axis having an orientation distribution predominantly in a range of from 25 degrees to 50 degrees relative to normal of a face of the substrate;
- wherein at least one of the first growth step or the second growth step comprises ejection of metal atoms from a target surface of a linear sputtering apparatus to (i) transit through a collimator comprising multiple collimator apertures and through a deposition aperture, and (ii) react with a gas species and be received by the at least one resonator device complex, wherein the target surface is arranged non-parallel to a face of the substrate.
Dependencies are inferred from the claim text.