Method for fabricating film bulk acoustic resonator (FBAR) device
First Claim
1. A method of fabricating a film bulk acoustic resonator (FBAR) device, said device comprising a series resonator and a shunt resonator, said method comprising the steps of:
- (a) preparing a substrate;
(b) forming an insulating layer on the substrate;
(c) forming a sacrificial layer on the insulating layer;
(d) forming a plurality of sacrificial regions by selectively removing the sacrificial layer;
(e) forming a membrane support layer on the insulating layer with the selectively removed sacrificial layer;
(f) forming a membrane layer on the sacrificial regions and the membrane support layer;
(g) forming a plurality of active regions in the membrane layer and on the sacrificial regions so that a thickness of the active region corresponding to the series resonator differs from a thickness of the active region corresponding to the shunt resonator;
(h) forming lower electrodes on the membrane layer including the active regions;
(i) forming an piezoelectric layer on the lower electrodes;
(j) forming upper electrodes on the piezoeleciric layer; and
(k) forming air-gaps by removing the sacrificial regions;
wherein the thicknesses of the active regions of the membrane layer are less than those of other regions of the membrane layer.
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Abstract
A method for fabricating an FBAR device includes (a) preparing a substrate; (b) forming an insulating layer on the substrate; (c) forming a sacrificial layer on the insulating layer; (d) forming a plurality of sacrificial regions for forming air-gaps by selectively removing the sacrificial layer; (e) forming a membrane support layer on the insulating layer with the selectively removed sacrificial layer; (f) forming a membrane layer on the sacrificial regions and the membrane support layer; (g) forming a plurality of active regions on the sacrificial regions of the membrane layer so that a thickness of the active region corresponding to a series resonator differs from a thickness of the active region corresponding to a shunt resonator of the FBAR; (h) forming lower electrodes on the membrane layer including the active regions; (i) forming a piezoelectric layer on the lower electrodes; (j) forming upper electrodes on the piezoelectric layer; and (k) forming the air-gaps by removing the sacrificial regions.
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Citations
9 Claims
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1. A method of fabricating a film bulk acoustic resonator (FBAR) device, said device comprising a series resonator and a shunt resonator, said method comprising the steps of:
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(a) preparing a substrate; (b) forming an insulating layer on the substrate; (c) forming a sacrificial layer on the insulating layer; (d) forming a plurality of sacrificial regions by selectively removing the sacrificial layer; (e) forming a membrane support layer on the insulating layer with the selectively removed sacrificial layer; (f) forming a membrane layer on the sacrificial regions and the membrane support layer; (g) forming a plurality of active regions in the membrane layer and on the sacrificial regions so that a thickness of the active region corresponding to the series resonator differs from a thickness of the active region corresponding to the shunt resonator; (h) forming lower electrodes on the membrane layer including the active regions; (i) forming an piezoelectric layer on the lower electrodes; (j) forming upper electrodes on the piezoeleciric layer; and (k) forming air-gaps by removing the sacrificial regions; wherein the thicknesses of the active regions of the membrane layer are less than those of other regions of the membrane layer. - View Dependent Claims (2)
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3. A method of fabricating a film bulk acoustic resonator (FBAR) device, said device comprising a series resonator and a shunt resonator, said method comprising the steps of:
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(a) preparing a substrate; (b) forming an insulating layer on the substrate; (c) forming a sacrificial layer on the insulating layer; (d) forming a plurality of sacrificial regions by selectively removing the sacrificial layer; (e) forming a membrane support layer on the insulating layer with the selectively removed sacrificial layer; (f) forming a membrane layer on the sacrificial regions and the membrane support layer; (g) forming a plurality of active regions in the membrane layer and on the sacrificial regions by an etching process so that the thickness of the active region corresponding to the series resonator differs from the thickness of the active region corresponding to the shunt resonator; (h) forming lower electrodes on the membrane layer including the active regions; (i) forming an piezoelectric layer on the lower electrodes; (j) forming upper electrodes on the piezoelectric layer; and (k) forming air-gaps by removing the sacrificial regions, wherein center frequencies of the series resonator and the shunt resonator are controlled by adjusting the thicknesses of the active regions of the membrane layer in step (g).
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4. A method of fabricating a film bulk acoustic resonator (FBAR) device, said device comprising a series resonator and a shunt resonator, said method comprising:
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forming an insulating layer on top a substrate; selectively forming sacrificial portions on top said insulating layer; forming a membrane support layer on top the insulating layer and around said sacrificial portions; forming a membrane layer on top both the sacrificial portions and the membrane support layer; forming a photoresist layer on top of said membrane layer; selectively etching both said photoresist layer and said membrane layer from active regions corresponding to the sacrificial portions; completely removing said photoresist layer after said selectively etching; forming lower electrodes on top the membrane layer including the active regions; forming an piezoelectric layer on top the lower electrodes; forming upper electrodes on top the piezoelectric layer; and forming air-gaps by removing the sacrificial portions; wherein the thickness of said membrane layer in the active region corresponding to the series resonator differs from the thickness of said membrane layer in the active region corresponding to the shunt resonator for controlling center frequencies of the series resonator and the shunt resonator. - View Dependent Claims (5, 6, 7, 8, 9)
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Specification