Contour-Mode Piezoelectric Micromechanical Resonators
A contour mode micromechanical piezoelectric resonator. The resonator has a bottom electrode; a top electrode; and a piezoelectric layer disposed between the bottom electrode and the top electrode. The piezoelectric resonator has a planar surface with a cantilevered periphery, dimensioned to undergo in-plane lateral displacement at the periphery. The resonator also includes means for applying an alternating electric field across the thickness of the piezoelectric resonator. The electric field is configured to cause the resonator to have a contour mode in-plane lateral displacement that is substantially in the plane of the planar surface of the resonator, wherein the fundamental frequency for the displacement of the piezoelectric resonator is set in part lithographically by the planar dimension of the bottom electrode, the top electrode or the piezoelectric layer.
1 - 46 . (canceled)
47 . A micromechanical in-plane oscillating piezoelectric resonator, comprising:
a bottom electrode;
a top electrode;
a thin film piezoelectric layer disposed between said bottom electrode and said top electrode, said piezoelectric resonator having a planar surface having a cantilevered periphery, dimensioned to undergo in-plane lateral displacement;
at least one micro via connected with the bottom electrode, said micro via configured to electrically connect the bottom electrode with a source of an alternating electric field; and
means for applying the alternating electric field across the thickness of said piezoelectric resonator, said electric field configured to cause said piezoelectric layer to have an in-plane lateral displacement that is substantially in the plane of said planar surface, wherein a center frequency of said piezoelectric resonator is set in part lithographically by the planar dimensions of at least one of said bottom electrode, said top electrode and said piezoelectric layer.
48 . The resonator of claim 47 , further comprising means for applying a DC voltage across the thickness of the piezoelectric resonator, said DC voltage configured for tuning the center frequency of the resonator.
49 . The resonator of claim 47 , wherein said center frequency of the resonator is set at least in part by a pattern on the top or bottom electrodes.
50 . The resonator of claim 47 , wherein a bandwidth of the resonator is set at least in part in part lithographically.
51 . The resonator of claim 47 , wherein an impedance of the resonator is set at least in part in part lithographically.
52 . The resonator of claim 47 , further comprising:
a substantially planar substrate for holding the resonators, and
at least one micromechanical piezoelectric resonator disposed on the planar substrate, wherein the resonators are interconnected either in parallel or in series.
53 . The resonator of claim 52 , wherein the planar substrate is made of silicon.
54 . The resonator of claim 52 , wherein the planar substrate is made of glass.
55 . The resonator of claim 47 , further comprising at least one tether anchoring the resonator to a substrate or other resonator.
56 . The resonator of claim 55 , wherein said tether comprises at least one routing trace for routing electrical signals to the electrodes.
57 . The resonator of claim 47 , wherein said means for applying an alternating electric field comprise electrical interconnects to the top electrode and the bottom electrode.
58 . The resonator of claim 47 , wherein said bottom electrode is lithographically patterned to excite a specific region or regions of the piezoelectric resonator.
59 . The resonator of claim 47 , wherein said top electrode is lithographically patterned to excite a specific region or regions of the piezoelectric resonator.
60 . The resonator of claim 47 , wherein said piezoelectric layer is a layer selected from the group consisting of aluminum nitride, gallium nitride, aluminum gallium arsenide, zinc oxide, quartz, and combinations thereof.
61 . The resonator of claim 47 , wherein said bottom or said top electrode is made from a material selected from the group consisting of aluminum, platinum, tungsten, molybdenum, ruthenium, chrome, gold, titanium, doped polycrystalline silicon, and combinations thereof.
62 . The resonator of claim 47 being a part of an array of resonators formed by mechanically coupling the resonators in said array to one another using said tethers.
63 . The resonator of claim 47 , wherein said one or more tethers are configured for use as electrical connectors for exchanging electrical signals with the piezoelectric resonator.
64 . The resonator of claim 63 being one of more than one resonator and wherein said more than one resonators are electrically cascaded to form a network of said resonators.
65 . The resonator of claim 64 , wherein said network is a Pi, T, L, shunt, or series network.
66 . The resonator of claim 65 being a part of a band pass filter circuit formed using a series of either of said Pi, T, L, series, or shunt networks.
67 . The resonator of claim 65 , comprising 2 or more resonators that are electrically connected.
68 . The resonator of claim 65 , comprising electrical connectors used to route the signal from one resonator to the next.
69 . The resonator of claim 47 being one of more than one resonator and wherein said more than one resonator are connected and arranged as a band-pass filter circuit.
70 . The resonator of claim 47 , wherein said piezoelectric resonator is a part of a frequency reference in an oscillator circuit.
71 . The resonator of claim 47 , wherein said piezoelectric resonator is a part of a band pass filter circuit.
72 . The resonator of claim 47 , wherein said piezoelectric layer has a shape selected from the group consisting of a rectangle, a circle, a polygon, a circular annulus, a rectangular annulus, a polygonal annulus and combinations thereof.