Method of fabricating rare-earth doped piezoelectric material with various amounts of dopants and a selected C-axis orientation
AssigneeAvago Technologies General IP (Singapore) Pte. Ltd.
InventorsJohn D. Larson, III, Jyrki Kaitila, Stefan Bader
Life of this patent
Estimating the term…
Abstract
A method of fabricating a rare-earth element doped piezoelectric material having a first component, a second component and the rare-earth element. The method includes: providing a substrate; initially flowing hydrogen over the substrate; after the initially flowing of the hydrogen over the substrate, flowing the first component to form the rare-earth element doped piezoelectric material over a surface of a target, the target comprising the rare-earth metal in a certain atomic percentage; and sputtering the rare-earth element doped piezoelectric material from the target on the substrate.
Claims21
A BAW resonator, comprising:
- a first electrode disposed over a substrate;
- an electropositive seed layer comprising aluminum and scandium (Al—Sc), and disposed over the substrate;
- a piezoelectric layer disposed over the electropositive seed layer and comprising a rare-earth element doped piezoelectric material having a compression-negative (CN) polarity, wherein the electropositive seed layer fosters growth of the piezoelectric layer having the compression-negative (CN) polarity;
- and
- a second electrode disposed over the rare-earth element doped piezoelectric material.
A bulk acoustic wave (BAW) resonator structure, comprising:
- a first electrode disposed over a substrate;
- a first non-ferroelectric piezoelectric layer disposed over the first electrode, the first non-ferroelectric piezoelectric layer having a first c-axis oriented along a first direction, and comprising a rare-earth element doped non-ferroelectric piezoelectric material;
- a second electrode disposed over the first non-ferroelectric piezoelectric layer;
- a second non-ferroelectric piezoelectric layer disposed over the first electrode, the second non-ferroelectric piezoelectric layer being adjacent to, and in direct contact with, the first non-ferroelectric piezoelectric layer, wherein the second non-ferroelectric piezoelectric layer has a second c-axis oriented in a second direction that is substantially antiparallel to the first direction;
- and
- an acoustic reflector disposed in the substrate.
A bulk acoustic wave (BAW) resonator structure, comprising:
- a first electrode disposed over a substrate;
- a cavity beneath the first electrode;
- a first non-ferroelectric piezoelectric layer disposed over the first electrode, the first non-electric piezoelectric layer comprising a rare-earth element doped non-ferroelectric piezoelectric material, and having a first c-axis oriented along a first direction;
- a second electrode disposed over the first non-ferroelectric piezoelectric layer, wherein an active region of the BAW resonator structure comprises an overlap of the first electrode and the second electrode with the cavity;
- and
- a second non-ferroelectric piezoelectric layer disposed over the first electrode, the second non-ferroelectric piezoelectric layer being adjacent to, and in direct contact with, the first non-ferroelectric piezoelectric layer, the second non-ferroelectric piezoelectric layer having a second c-axis oriented in a second direction that is substantially antiparallel to the first direction, wherein the second electrode overlaps the second non-ferroelectric piezoelectric layer;
- and
- an acoustic reflector disposed in the substrate.
Dependencies are inferred from the claim text.