Abstract: A coupled resonator filter and a method of fabricating the coupled resonator filter are provided. The method includes: sequentially stacking a first electrode, a first piezoelectric layer, a second electrode, an insulating layer, a third electrode, a second piezoelectric layer, and a fourth electrode on a surface of a substrate; sequentially patterning the first electrode, the first piezoelectric layer, the second electrode, the insulating layer, the third electrode, the second piezoelectric layer, and the fourth electrode to expose areas of the first, second, and third electrodes; forming a plurality of connection electrodes respectively connected to the exposed areas of the first, second, and third electrodes and an area of the fourth electrode; and etching an area of the substrate underneath the first electrode to form an air gap.

Abstract: A method of multi-stage substrate etching is provided.

Abstract: A duplexer which prevents effects between transmitter and receiver filters. The duplexer include a substrate, a transmitter filter fabricated in a predetermined first area on a surface of the substrate, a receiver filter fabricated in a predetermined second area on the surface of the substrate and an air cavity fabricated in an area between the predetermined first and second areas by etching the substrate to isolate the transmitter and receiver filters from each other. The air cavity is fabricated in the substrate perpendicular to directions along which the transmitter and receiver filters are disposed. Accordingly, physical effects among elements can be effectively intercepted.

Abstract: A filter using an air gap type film bulk acoustic resonator is provided. The present filter includes a substrate on which a first port, a second port, and a ground port are formed to be connected to an external terminal; at least one first film bulk acoustic resonator serially connecting the first port to the second port on the substrate; at least one second film bulk acoustic resonator parallel connected to an interconnection node formed between the first port and the second port; and at least one inductor serially connecting the second film bulk acoustic resonator to the ground port. The inductor included in the filter is fabricated with the first and second film bulk acoustic resonators as one body. Accordingly, a small-sized filter may be fabricated through a simplified process.

Abstract: A radio frequency (RF) module and a multi RF module including the same include a base substrate, a first element capable of processing RF signals formed on the base substrate, a second element capable of processing RF signals separated from and disposed over the first element, a cap substrate coupled with the base substrate to encapsulate the first and second elements including a plurality of through electrodes that electrically connect the first and second elements to the outside, and a bonding pad that encapsulates and joins the base substrate and the cap substrate and electrically connects the first and second elements to the through electrodes.

Abstract: A coupled resonator filter and a method of fabricating the coupled resonator filter are provided. The method includes: sequentially stacking a first electrode, a first piezoelectric layer, a second electrode, an insulating layer, a third electrode, a second piezoelectric layer, and a fourth electrode on a surface of a substrate; sequentially patterning the first electrode, the first piezoelectric layer, the second electrode, the insulating layer, the third electrode, the second piezoelectric layer, and the fourth electrode to expose areas of the first, second, and third electrodes; forming a plurality of connection electrodes respectively connected to the exposed areas of the first, second, and third electrodes and an area of the fourth electrode; and etching an area of the substrate underneath the first electrode to form an air gap.

Abstract: An inductor integrated chip and fabrication method thereof is provided. The inductor integrated chip includes a wafer; an inductor bonded on a surface of the wafer; a circuit element formed on the surface of the wafer and coupled to a first end of the inductor; a packaging wafer connected to the surface of the wafer and packaging the inductor and the circuit element; and a connecting electrode formed on the packaging wafer and connected to a second end of the inductor. The method includes forming an inductor and a circuit element on a surface of a wafer, wherein the circuit element is coupled to a first end of the inductor; forming a connecting electrode on a packaging wafer; and packaging the inductor and the circuit element by joining the wafer and the packaging wafer so as to connect the connecting electrode with a second end of the inductor.

Abstract: A duplexer which prevents effects between transmitter and receiver filters. The duplexer include a substrate, a transmitter filter fabricated in a predetermined first area on a surface of the substrate, a receiver filter fabricated in a predetermined second area on the surface of the substrate and an air cavity fabricated in an area between the predetermined first and second areas by etching the substrate to isolate the transmitter and receiver filters from each other. The air cavity is fabricated in the substrate perpendicular to directions along which the transmitter and receiver filters are disposed. Accordingly, physical effects among elements can be effectively intercepted.

Abstract: A method and apparatus for vacuum-mounting at least one micro electro mechanical system (MEMS) on a substrate includes a gas injecting section for injecting an inert gas into a vacuum chamber; a substrate aligning section for aligning a semiconductor substrate and a cover, the cover having a cavity formed therein and a getter attached to an interior surface of the cavity; a bonding section for bonding the semiconductor substrate and the cover together; and a controlling section for controlling the substrate aligning section to align the semiconductor and the cover, for controlling the gas injecting section to inject the inert gas into the vacuum chamber, and for controlling the bonding section to bond the semiconductor substrate and the cover together after the inert gas is injected.

Abstract: A film bulk acoustic resonator (FBAR) including a substrate having an etched air gap therethrough; a resonance part having a first electrode, a piezoelectric film and a second electrode which are laminated in turn above the air gap; and an etching resistance layer disposed between the air gap and the resonance part to limit an etching depth in forming the air gap, thereby preventing damage to the resonance part.

Abstract: A method of fine patterning a metal layer which includes depositing a metal layer on a substrate; depositing, on the metal layer, a mask layer having a different degree of electrolytic dissociation than that of the metal layer; making a patterned substrate body; and dipping the substrate body into an electrolyte to thereby corrode the metal layer by an electric potential generated between the metal layer and the mask layer to obtain a desired pattern. The metal layer is a metal having a high degree of electrolytic dissociation for use as an anode, and the mask layer is a metal having a low degree of electrolytic dissociation for use as a cathode. Accordingly, the present invention can conduct fine patterning of a metal layer to a desired size.

Abstract: A method of forming a via hole through a glass wafer includes depositing a material layer on an outer surface of the glass wafer, the material layer having a selection ratio higher than that of the glass wafer, forming a via-patterned portion on one side of the material layer, performing a first etching in which the via-patterned portion is etched to form a preliminary via hole, eliminating any remaining patterning material used in the formation of the via-patterned portion, performing a second etching in which the preliminary via hole is etched to form a via hole having a smooth surface and extending through the glass wafer, and eliminating the material layer. The method according to the present invention is able to form a via hole through a glass wafer without allowing formation of an undercut or minute cracks, thereby increasing the yield and reliability of MEMS elements.

Abstract: A band filter using a film bulk acoustic resonator and a method of fabricating the same. The method includes the steps of forming a membrane layer on a substrate, forming a plurality of resonators on an upper surface of the membrane layer, depositing a mask layer on a lower surface of the membrane layer and patterning the mask layer to form a plurality of main windows and sub windows, and forming cavities along the main windows in the substrate and forming sub walls in the cavities in such a way that the sub walls are separated apart from the membrane layer by using the notch effect caused during a dry etching. It is possible to precisely form cavities with desired sizes even if the cavities have different sizes, to reduce the notched areas in the cavities, to reduce the total size of the filter by decreasing a distance between the cavities and to reduce the total length of wires.

Abstract: A subminiature, high-performance monolithic duplexer is disclosed. The monolithic duplexer includes a substrate, a transmitting-end filter formed in a first area on an upper surface of the substrate, a receiving-end filter formed in a second area on the upper surface of the substrate, a packaging substrate, bonded on an area on the upper surface of the substrate, for packaging the transmitting-end filter and the receiving-end filter in a sealed state, and a phase shifter, formed on one surface of the packaging substrate and connected to the transmitting-end filter and the receiving-end filter, respectively, for intercepting a signal inflow between the transmitting-end filter and the receiving-end filter.

Abstract: A filter using an air gap type film bulk acoustic resonator is provided. The present filter includes a substrate on which a first port, a second port, and a ground port are formed to be connected to an external terminal; at least one first film bulk acoustic resonator serially connecting the first port to the second port on the substrate; at least one second film bulk acoustic resonator parallel connected to an interconnection node formed between the first port and the second port; and at least one inductor serially connecting the second film bulk acoustic resonator to the ground port. The inductor included in the filter is fabricated with the first and second film bulk acoustic resonators as one body. Accordingly, a small-sized filter may be fabricated through a simplified process.

Abstract: A metal wiring method for an undercut in a MEMS packaging process includes disposing a MEMS element on a silicon substrate, welding a glass wafer to an upper portion of the silicon substrate having the MEMS element disposed thereon, the glass wafer having a hole formed therein for connecting a metal wiring, depositing a thin metal film for the metal wiring in the hole, and ion-mealing the deposited thin metal film. By the ion-mealing, the method is capable of connecting a metal wiring to a via hole having an undercut.

Abstract: A metal wiring method for an undercut in a MEMS packaging process includes disposing a MEMS element on a silicon substrate, welding a glass wafer to an upper portion of the silicon substrate having the MEMS element disposed thereon, the glass wafer having a hole formed therein for connecting a metal wiring, depositing a thin metal film for the metal wiring in the hole, and ion-mealing the deposited thin metal film. By the ion-mealing, the method is capable of connecting a metal wiring to a via hole having an undercut.

Abstract: A method and apparatus for vacuum-mounting at least one micro electro mechanical system (MEMS) on a substrate includes a gas injecting section for injecting an inert gas into a vacuum chamber; a substrate aligning section for aligning a semiconductor substrate and a cover, the cover having a cavity formed therein and a getter attached to an interior surface of the cavity; a bonding section for bonding the semiconductor substrate and the cover together; and a controlling section for controlling the substrate aligning section to align the semiconductor and the cover, for controlling the gas injecting section to inject the inert gas into the vacuum chamber, and for controlling the bonding section to bond the semiconductor substrate and the cover together after the inert gas is injected.

Abstract: A method of forming a via hole through a glass wafer includes depositing a material layer on an outer surface of the glass wafer, the material layer having a selection ratio higher than that of the glass wafer, forming a via-patterned portion on one side of the material layer, performing a first etching in which the via-patterned portion is etched to form a preliminary via hole, eliminating any remaining patterning material used in the formation of the via-patterned portion, performing a second etching in which the preliminary via hole is etched to form a via hole having a smooth surface and extending through the glass wafer, and eliminating the material layer. The method according to the present invention is able to form a via hole through a glass wafer without allowing formation of an undercut or minute cracks, thereby increasing the yield and reliability of MEMS elements.

Abstract: An evaporator of a capillary pumped loop (CPL) cooling apparatus having a fine wick structure is provided. The evaporator having a flat board shape, of a capillary pumped loop (CPL) cooling apparatus includes a coolant storing part for storing in-flowing coolant from the condenser and collecting a uncondensed gas contained in the in-flowing coolant in an upper space, a cooling part for cooling the heating body through vaporization of the coolant, and superstructure and substructure combined with each other, for defining a channel region in which the coolant flows from the coolant storing part to the cooling part by a capillary action. In this case, the substructure includes a first substructure used as a substrate and a second substructure formed along a border of the substrate, or includes first through third segments equal to the first and second substructures.