Method for making thin film bulk acoustic resonators (FBARS) with different frequencies on a single substrate and apparatus embodying the method
AssigneeAgilent Technologies, Inc.
InventorsRichard C. Ruby, John D. Larson, III, Paul D. Bradley
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Abstract
A method for fabricating a resonator, and in particular, a thin film bulk acoustic resonator (FBAR), and a resonator embodying the method are disclosed. An FBAR is fabricated on a substrate by introducing a mass loading top electrode layer. For a substrate having multiple resonators, the top mass loading electrode layer is introduced for only selected resonator to provide resonators having different resonance frequencies on the same substrate.
Claims19
A method of fabricating a resonator on a substrate, the method comprising:
- fabricating a bottom electrode;
- fabricating a piezoelectric (PZ) layer;
- fabricating a top electrode layer;
- fabricating a top loading layer above a section of said top electrode layer;
- and
- over etching the top loading layer with said top electrode layer at the same step such that the top loading layer and the top electrode layer are etched to form a top electrode.
A method of fabricating an apparatus resonator on a substrate, the method comprising:
- fabricating a first bottom electrode and a second bottom electrode;
- fabricating a piezoelectric (PZ) layer over both the first and the second bottom electrodes, the PZ layer having a first portion above the first bottom electrode and a second portion above the second bottom electrode;
- fabricating a top electrode layer having a first section above the first portion and a second section over the second portion;
- fabricating a top loading layer above the first section;
- and
- over etching the top loading layer such that the top loading layer and the top electrode layer are etched to form a first top electrode.
Dependencies are inferred from the claim text.