Embodiments of the present invention provide a small and well-characterized bulk acoustic wave device by fabricating a filter having a wide band width or a resonator having a wide oscillation frequency range together with a semiconductor circuit. In embodiments of the present invention, a bulk acoustic wave device comprises a semiconductor substrate having a dielectric substance layer thereon, the dielectric substance layer has a ground conductor layer thereon, the ground conductor layer has a piezoelectric ceramic thin film thereon and the piezoelectric ceramic thin film has a conductive electrode pattern thereon. The thickness of the piezoelectric ceramic thin film is more than ten times the thickness of the ground conductor layer, and the wave number of acoustic waves that propagate in a direction parallel to a surface of the piezoelectric ceramic thin film multiplied by the thickness of the piezoelectric ceramic thin film is less than 2.

Film bulk acoustic wave device

Self-aligned, opposed, nanometer dimension tips (12, 22) are fabricated in pairs, one of each pair being located on a movable (24) single crystal beam, with the beam being movable in three dimensions with respect to a substrate (18) carrying the other tip (12) of a pair. Motion of one tip with respect to the other is controlled or sensed by transducers (120, 122, 124, 126) formed on the supporting beams (62, 64). Spring means (76, 80, 86, 88) in each beam allow axial motion of the beam. The tips (12, 22) and beams (62, 64) are fabricated from single crystal silicon substrate (18) and the tips (12, 22) may be electrically isolated from the substrate (18) by fabricating insulating segments (40, 54) in the beam structure.

Methods of fabricating integrated, aligned tunneling tip pairs

A selective chemical vapor deposition (CVD) tungsten process is used to fabricate three-dimensional tungsten cantilever beams on a substrate. Two beams form micromechanical tweezers that move in three dimensions by the application of potential differences between the beams, and between the beams and the silicon substrate. A high deposition rate selective tungsten CVD process is used to fabricate beams of greater than 3 micrometers thickness in patterned, CVD silicon dioxide trenches ion-implanted with silicon. Tweezers 200 micrometers in length with a cross section of 2.7 by 2.5 micrometers will close upon application of a voltage of less than 150 volts.

Microdynamic release structure

A selective chemical vapor deposition (CVD) tungsten process is used to fabricate three-dimensional tungsten cantilever beams on a silicon substrate. Two beams form micromechanical tweezers that move in three dimensions by the application of potential differences between the beams, and between the beams and the silicon substrate. A high-deposition-rate selective tungsten CVD process is used to fabricate beams of greater than three microns thickness in patterned CVD SiO/sub 2/ trenches ion-implanted with silicon. Tweezer 200- mu m in length with a cross section of 2.7 mu m*2.5 mu m close with an applied voltage of less than 150 V. The magnitude of the deflection and the beam profile are compared to results obtained using simulations of the electric field and dynamic mechanical simulations of the tweezers. >

Selective chemical vapor deposition of tungsten for microdynamic structures

Integrated circuits utilizing piezoelectric elements can be advantageously constructed by bonding elements together via direct bonds. Such integrated circuits include an electro-acoustic hybrid integrated circuit such as a voltage controlled oscillator wherein a semiconductor substrate having an active element is bonded through direct bonding to a surface acoustic wave resonator or a quartz oscillator as an electro-acoustic element. A quartz device can also be provided which includes a quartz plate, excitation electrodes on opposite surfaces, and a holding member made of a material having a thermal expansion coefficient substantially equal to that of the quartz plate. The holding member is connected to the quartz plate by direct bonding without using any adhesives. Because the thermal expansion coefficients of the quartz plate and the holding member are equal, no thermal stress occurs in the bonding area. As a result, virtually no stress is applied to the quartz plate and the frequency-temperature characteristic can be improved. A piezoelectric filter according to the invention includes an oscillatory piezoelectric plate made of quartz, lithium tantalate, lithium niobate or lithium borate and having an oscillatory portion; a glass plate to which the piezoelectric plate is directly bonded; and first and second oscillatory electrode members which are provided on opposite faces of the oscillatory portion, respectively, such that at least one of the oscillatory electrode members is divided into a plurality of counter electrodes.

Methods of manufacture for electronic components having high-frequency elements

A surface-acoustic-wave parametric device characterized in that a width of a parametric interaction region in a direction perpendicular to the propagation direction of surface acoustic wave is varied so as to correspond to a desired frequency characteristic.

Shoichi Minagawa

Papers

Surface-acoustic-wave parametric device