Patent ID: 7185540
Filing Date: 2007-03-06
Classification: B41J,G01C,G01P,H01L

Abstract:
1. 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, 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 an alloyed noble metal containing at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper; the piezoelectric layer is made of a rhombohedral or tetragonal perovskite oxide that is preferentially oriented along a (001) plane; a portion of the piezoelectric layer that is closer to the first electrode layer has a structure in which a (001)-oriented region extends over the at least one metal in a portion of a surface of the first electrode layer that is closer to the piezoelectric layer, and a cross-sectional area of the (001)-oriented region taken along a plane perpendicular to a thickness direction of the piezoelectric layer gradually increases in a direction away from the first electrode layer toward the second electrode layer; and the at least one metal forms pattern in the first electrode to control a growth direction of the piezoelectric layer.