Abstract: A film bulk acoustic resonator (FBAR) includes an insulation layer on a substrate to prevent a signal from being transmitted to a substrate. The FBAR includes a portion of a membrane layer corresponding to an activation area to adjust a resonance frequency band and improve a transmission gain of the resonance frequency band, the portion of the membrane layer being partially etched to have a thickness less than the other portion of the membrane layer. A method of forming the FBAR includes forming an sacrificing layer made of polysilicon, forming an air gap using a dry etching process, and forming a via hole. The method prevents structural problems occurred in a conventional air gap forming process and provides locations and the number of the via holes to be controlled.

Abstract: FBAR device includes a membrane supporting layer between a substrate and a membrane layer, surrounding an air gap region. The membrane supporting layer support the membrane layer to obtain a robust structure. The substrate has a first area and a second area surrounding the first area. The membrane supporting layer is formed on the second area of the substrate so as to form the air gap on the first area of the substrate. The membrane layer is formed on the membrane supporting layer and the air gap. A first electrode is formed on a portion of the membrane layer. A piezoelectric layer is formed on a portion of the first electrode. A second electrode is formed on a portion of the piezoelectric layer.

Abstract: A film bulk acoustic resonator (FBAR) includes an insulation layer on a substrate to prevent a signal from being transmitted to a substrate. The FBAR includes a portion of a membrane layer corresponding to an activation area to adjust a resonance frequency band and improve a transmission gain of the resonance frequency band, the portion of the membrane layer being partially etched to have a thickness less than the other portion of the membrane layer. A method of forming the FBAR includes forming an sacrificing layer made of polysilicon, forming an air gap using a dry etching process, and forming a via hole. The method prevents structural problems occurred in a conventional air gap forming process and provides locations and the number of the via holes to be controlled.

Abstract: The present invention provides a robust FBAR device and a simplified method of fabricating a FBAR device. FBAR device according to the present invention includes a membrane supporting layer between a substrate and a membrane layer, surrounding an air gap region. The membrane supporting layer supports the membrane layer to obtain a robust structure. Firstly, the method forms a sacrificial layer on the substrate, then a photoresist pattern is formed on air gap forming region at a top surface of the sacrificial layer, the method removes the sacrificial layer to form a sacrificial pattern by using the photoresist pattern as an etching mask. An insulating material then deposits on the substrate, the photoresist pattern is remove, and a membrane layer is formed on a top surface of the sacrificial layer and the insulating material layer. Finally, the method removes the sacrificial pattern to form an air gap.

Abstract: The present invention provides a robust FBAR device and a simplified method of fabricating a FBAR device. FBAR device according to the present invention includes a membrane supporting layer between a substrate and a membrane layer, surrounding an air gap region. The membrane supporting layer supports the membrane layer to obtain a robust structure. Firstly, the method forms a sacrificial layer on the substrate, then a photoresist pattern is formed on air gap forming region at a top surface of the sacrificial layer, the method removes the sacrificial layer to form a sacrificial pattern by using the photoresist pattern as an etching mask. An insulating material then deposits on the substrate, the photoresist pattern is remove, and a membrane layer is formed on a top surface of the sacrificial layer and the insulating material layer. Finally, the method removes the sacrificial pattern to form an air gap.

Abstract: The present invention provides a robust FBAR device and a simplified method of fabricating a FBAR device. FBAR device according to the present invention includes a membrane supporting layer between a substrate and a membrane layer, surrounding an air gap region. The membrane supporting layer supports the membrane layer to obtain a robust structure. Firstly, the method forms a sacrificial layer on the substrate, then a photoresist pattern is formed on air gap forming region at a top surface of the sacrificial layer, the method removes the sacrificial layer to form a sacrificial pattern by using the photoresist pattern as an etching mask. An insulating material then deposits on the substrate, the photoresist pattern is remove, and a membrane layer is formed on a top surface of the sacrificial layer and the insulating material layer. Finally, the method removes the sacrificial pattern to form an air gap.

Abstract: A magnetic thin-film head fabrication method which improves the yield of the thin-film head by reducing the deviation of line widths for various regions of a pole layer includes the steps of forming an upper pole layer on a to-be-etched magnet-forming layer formed on a lower pole layer, forming a metallic seed layer on the upper pole layer, forming an insulating layer having an aperture corresponding to a desired pattern on the seed layer, forming a metal mask layer on the exposed plane of the seed layer by a plating method, removing the insulating layer and etching the exposed portion of the magnet-forming layer which is not covered by the metal mask layer to a predetermined depth. Since the pattern of the metal mask layer can be changed easily and precisely by the shape of the photoresist layer, the size deviation of the processed products due to processing error for each product is reduced, thereby maximizing the reproducibility of the upper pole layer.