Bulk acoustic wave device with integrated temperature sensor and heater
AssigneeTexas Instruments Incorporated
InventorsKeegan Shaun Martin, Ting-Ta Yen
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Abstract
An acoustic-wave device includes a first electrode located over a substrate. A piezoelectric film is located over the first electrode and at least partially overlaps the first electrode. A second electrode is located over the piezoelectric film and at least partially overlaps the first electrode and the piezoelectric film. A temperature sensor is located in a same layer level as the first or second electrode. A heater may also be located in a same layer level as the first electrode. A closed-loop system may operate using the temperature sensor and the heater to maintain an operating temperature that provides highly stable operation.
Claims22
An acoustic-wave device, comprising:
- a first electrode located over a substrate;
- a piezoelectric layer over the first electrode;
- a second electrode over the piezoelectric layer and at least partially overlapping the first electrode;
- and
- a temperature sensor in a same layer level as the first or second electrode.
A method of forming a resonator, comprising:
- forming a first electrode and a first resistor from a first metallic film over a substrate;
- forming a piezoelectric film over the first electrode;
- forming a second electrode over the first electrode from a second metallic film;
- and
- forming a second resistor from the second metallic film,
- configuring a controller to maintain an operating temperature of the piezoelectric film by directing current to a first one of the first and second resistors in response to a resistance of a second one of the first and second resistors, the operating temperature being greater than a specified maximum ambient temperature of the resonator.
A resonator, comprising:
- a first electrode and a first resistor in a first metallic layer over a substrate;
- a piezoelectric film over the first electrode and the first resistor;
- a second electrode over the first electrode in a second metallic layer;
- and
- a second resistor from the second metallic layer,
- a controller configured to maintain an operating temperature of the piezoelectric film by directing current to a first one of the first and second resistors in response to a resistance of a second one of the first and second resistors, the operating temperature being greater than a specified maximum ambient temperature of the resonator.
Dependencies are inferred from the claim text.