Patent ID: 7478558

Claim:
An angular velocity sensor, comprising a substrate including a fixed portion and at least a pair of vibrating portions extending from the fixed portion in a predetermined direction, in which a first electrode layer, an orientation control layer, a piezoelectric layer and a second electrode layer are layered in this order at least on each of the vibrating portions of the substrate, and the second electrode layer on each of the vibrating portions is patterned into at least one driving electrode for vibrating the vibrating portion in a width direction thereof and at least one detection electrode for detecting a displacement of the vibrating portion in a thickness direction thereof, wherein: the first electrode layer is made of a noble metal containing titanium or titanium oxide, the orientation control layer is made of a cubic or tetragonal perovskite oxide that is preferentially oriented along a (100) or (001) plane, the piezoelectric layer is made of a rhombohedral or tetragonal perovskite oxide that is preferentially oriented along a (001) plane, and in the vicinity of one surface of the orientation control layer that is closer to the first electrode layer, a (100)- or (001)-oriented region extends over titanium or titanium oxide located on one surface of the first electrode layer that is closer to the orientation control layer, and the cross-sectional area of the (100)- or (001)-oriented region in the direction perpendicular to the thickness direction gradually increases in the direction away from the first electrode layer toward the piezoelectric layer.