Abstract: A bulk acoustic wave resonator includes: a substrate; a first electrode disposed on the substrate; a piezoelectric layer at least partially disposed on the first electrode; and a second electrode disposed on the piezoelectric layer; wherein the first electrode includes an aluminum alloy layer containing scandium (Sc), and has a surface roughness of 2.4 nm or less, based on an arithmetic mean roughness.

Abstract: A bulk acoustic wave resonator includes a substrate; and a resonator including a first electrode, a piezoelectric layer, and a second electrode sequentially disposed on the substrate. Either one or both of the first electrode and the second electrode includes an alloy of molybdenum (Mo) and tantalum (Ta).

Abstract: A bulk-acoustic wave resonator includes: a substrate; a seed layer disposed on the substrate, and having a hexagonal crystal structure; a bottom electrode disposed on the seed layer; a piezoelectric layer at least partially disposed on the bottom electrode; and a top electrode disposed on the piezoelectric layer, wherein either one or both of the bottom electrode and the top electrode includes a scandium (Sc)-containing aluminum alloy layer.

Abstract: A bulk-acoustic wave resonator includes a substrate, a first electrode disposed on the substrate, a piezoelectric layer, of which at least a portion is disposed on the first electrode, a second electrode disposed on the piezoelectric layer, and a passivation layer disposed to cover the first electrode and the second electrode. Either one or both of the first electrode and the second electrode includes an aluminum alloy layer. Either one or both of the piezoelectric layer and the passivation layer has aluminum nitride, or aluminum nitride added with a doping material, having a ratio of an out-of-plane lattice constant “c” to an in-plane lattice constant “a” (c/a) of less than 1.58.

Abstract: A fine dust concentration sensor includes a bulk acoustic resonator and a cap including an upper portion with holes therein and a lateral portion connected to the upper portion to accommodate the bulk acoustic resonator. An upper surface of the upper portion of the cap is coated with a hydrophobic material.

Abstract: A piezoelectric oscillator, and method of making the same, includes an oscillation substrate comprising an oscillating part and a surrounding part, wherein the surrounding part is thinner than the oscillating part, and oscillating electrodes disposed on an upper surface and a lower surface of the oscillating part. The oscillation substrate is configured according to H=400.59×S+1.75±1.5, wherein H=100×(T2/T1) and S=T2/(L1?L2), wherein L1 represents an entire length of the oscillation substrate, L2 represents a length of the oscillating part, T1 represents a thickness of the oscillating part, and T2 represents a step height between the oscillating part and the surrounding part.

Abstract: A bulk acoustic wave resonator includes: a substrate; a lower electrode disposed on the substrate; a piezoelectric layer at least partially disposed on the lower electrode; and an upper electrode disposed on the piezoelectric layer, wherein either one or both of the lower electrode and the upper electrode includes a layer of aluminum alloy including scandium (Sc).

Abstract: An acoustic resonator includes a substrate, a center portion, an extending portion, and a barrier layer. A first electrode, a piezoelectric layer, and a second electrode are sequentially stacked on the substrate in the central portion. The extending portion is configured to extend from the center portion, and includes an insertion layer disposed below the piezoelectric layer. The barrier layer is disposed between the first electrode and the piezoelectric layer.

Abstract: An acoustic resonator includes a membrane layer disposed on an insulating layer; a cavity formed by the insulating layer and the membrane layer and having a hydrophobic layer disposed on at least one of a portion of an upper surface of the cavity and a portion of a lower surface of the cavity; and a resonating portion disposed on the cavity and having a second electrode on a piezoelectric layer on a first electrode.

Abstract: A film bulk acoustic resonator includes: a first electrode disposed on a substrate; a piezoelectric body disposed on the first electrode and including AlN to which a dopant is added; and a second electrode disposed on the piezoelectric body and facing the first electrode such that the piezoelectric body is interposed between the second electrode and the first electrode, wherein the dopant includes either one of 0.1 to 24 at % of Ta and 0.1 to 23 at % of Nb.

Abstract: A bulk acoustic wave resonator includes a substrate; and a resonator including a first electrode, a piezoelectric layer, and a second electrode sequentially disposed on the substrate. Either one or both of the first electrode and the second electrode includes an alloy of molybdenum (Mo) and tantalum (Ta).

Abstract: A bulk acoustic wave resonator includes a substrate protective layer disposed on a top surface of a substrate, a cavity defined by a membrane layer and the substrate, and a resonating part disposed on the membrane layer. The membrane layer includes a first layer and a second layer, the second layer having the same material as the first layer and having a density greater than that of the first layer.

Abstract: Embodiments of the invention provide a quartz crystal vibrator including an AT-cut quartz crystal piece having a long side in an X axis direction and including first and second crystal planes formed on at least one side surface thereof in a Y? axis direction, and an electrode layer formed on the AT-cut quartz crystal piece.

Abstract: A piezoelectric oscillator, and method of making the same, includes an oscillation substrate comprising an oscillating part and a surrounding part, wherein a the surrounding part is thinner than the oscillating part, and oscillating electrodes disposed on an upper surface and a lower surface of the oscillating part. The oscillation substrate is configured according to H=400.59×X+1.75±1.5, wherein H=100×(T2/T1) and S=T2/(L1?L2), wherein L1 represents an entire length of the oscillation substrate, L2 represents a length of the oscillating part, T1 represents a thickness of the oscillating part, and T2 represents a step height between the oscillating part and the surrounding part.

Abstract: The present invention presents a piezoelectric piece for a piezoelectric vibrator and a manufacturing method thereof. The piezoelectric piece for a piezoelectric vibrator in accordance with an embodiment of the present invention includes: a base; and a vibrating arm connected to the base and having a groove formed therein. Here, one surface inside the groove includes: a first slope extended from an upper portion of the groove in a lower direction so as to have a first angle; and a second slope extended from a lower portion of the first slope in a lower direction so as to have a second angle that is greater than the first angle, and a rate of a depth of the first slope for a depth of the groove is greater than or equal to 0.5 and less than or equal to 1.

Abstract: There are provided a multi-axis sensor and a method for manufacturing the same. The multi-axis sensor includes: a first sensor mounted on a board and detecting inertial force; and a second sensor mounted on the board and detecting a position and a motion, wherein the first sensor and the board have a seal formed therebetween so as to prevent permeation from the outside and are electrically connected to each other.

Abstract: Embodiments of the invention provide a quartz crystal vibrator including an AT-cut quartz crystal piece having a long side in an X axis direction and including first and second crystal planes formed on at least one side surface thereof in a Y? axis direction, and an electrode layer formed on the AT-cut quartz crystal piece.

Abstract: Disclosed herein are a method of forming an amorphous alloy film and a printed wiring board manufactured by the same. The amorphous alloy film may be formed on a copper foil as one of rust-proofing treatment methods of the copper foil to thereby simultaneously show and improve corrosion-resistance and conductivity, and the amorphous alloy film may be formed by the sputtering deposition method, such that high melting point materials may be manufactured as a thin film at a relatively low temperature and the amorphous alloy film having strong adhesion strength with a substrate may be obtained.

Abstract: Embodiments of the invention provide a quartz vibrator and a method for manufacturing the same. The quartz vibrator includes a quartz substrate vibrating depending on an electrical signal, first and second electrodes formed on both surfaces of the quartz substrate, and a first protective layer including an opening corresponding to a trimming region of the first electrode and formed on the first electrode.

Abstract: Embodiments of the present invention provide a quartz vibrator and a method for manufacturing the same. The quartz vibrator includes a quartz substrate including an exciting part having a rectangular plate and a peripheral part having a thickness smaller than that of the exciting part and formed around the exciting part, a first electrode formed on one surface of the quartz substrate and the whole surface of the exciting part, and a second electrode formed on the other surface of the quartz substrate and the whole surface of the exciting part.