Method for bonding a microelectromechanical device
AssigneeMurata Manufacturing Co., Ltd.
InventorsMikko Partanen, Petteri Kilpinen
Life of this patent
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Abstract
A method is provided for bonding microelectromechanical components with at least two different pressure element cavities. The method includes forming on the cap wafer or/and on the structure wafer a metal layer that allows the hermetically sealing of one cavity at a first pressure, then hermetically scaling the other cavity at a second pressure.
Claims20
A method for manufacturing a microelectromechanical component that includes a structure wafer and a cap wafer that defines a horizontal xy-plane and a vertical z-direction that is perpendicular to the xy-plane, the cap wafer including a top surface, a bottom surface that includes glass regions, a first cap wafer sealing region and a second cap wafer sealing region that includes at least one of the glass regions, and the structure wafer includes top and bottom surfaces, and a first cavity and a second cavity, with a first microelectromechanical device structure in the first cavity and a second microelectromechanical device structure in the second cavity, the structure wafer further including a first structure wafer sealing region that surrounds the first cavity and a second structure wafer sealing region that surrounds the first cavity and the second cavity, the method comprising:
- forming a metal layer on at least one of the bottom surface of the cap wafer in the first cap wafer sealing region and the top surface of the structure wafer in the first structure wafer sealing region;
- placing the cap wafer on top of the structure wafer so that the first cap wafer sealing region is aligned with the first structure wafer sealing region along the z-axis, and the second cap wafer sealing region is aligned with the second structure wafer sealing region along the z-axis;
- fixing the cap wafer to the structure wafer in a surrounding first gas atmosphere so that the metal layer and the cap wafer form a hermetically sealing enclosure around outer edges of the first cavity;
- changing the surrounding first gas atmosphere to a surrounding second gas atmosphere;
- and
- anodically bonding the second cap wafer sealing region to the second structure wafer sealing region in the surrounding second gas atmosphere so that the second cavity is hermetically sealed.
A microelectromechanical component comprising:
- a cap wafer that defines a horizontal xy-plane and a vertical z-direction that is perpendicular to the xy-plane, the cap wafer including a top surface, a bottom surface that includes glass regions, a first cap wafer sealing region and a second cap wafer sealing region that includes at least one of the glass regions;
- a structure wafer including top and bottom surfaces, a first cavity, a second cavity, a first structure wafer sealing region that surrounds the first cavity, and a second structure wafer sealing region that surrounds the first cavity and the second cavity;
- a first microelectromechanical device structure in the first cavity;
- a second microelectromechanical device structure in the second cavity;
- and
- a metal layer on at least one of the bottom surface of the cap wafer in the first cap wafer sealing region and the top surface of the structure wafer in the first structure wafer sealing region;
- wherein the first cap wafer sealing region is aligned with the first structure wafer sealing region along the z-axis, and the second cap wafer sealing region is aligned with the second structure wafer sealing region along the z-axis,
- wherein the metal layer and the cap wafer form a hermetically sealing enclosure around outer edges of the first cavity, and
- wherein the second cap wafer sealing region is anodically bonded to the second structure wafer sealing region so that the second cavity is hermetically sealed at a different pressure than the first cavity.
Dependencies are inferred from the claim text.