Piezoelectric element, ink jet head, angular velocity sensor, manufacturing method thereof, and ink jet type recording apparatus

An ink jet head, comprising:

• a piezoelectric element in which a first electrode layer, an orientation control layer, a piezoelectric layer and a second electrode layer are layered in this order;
• a vibration layer provided on one surface of the piezoelectric element that is closer to the second electrode layer;
• and a pressure chamber member bonded to one surface of the vibration layer that is away from the piezoelectric element and including a pressure chamber for storing ink therein, in which the vibration layer is displaced in a thickness direction by a piezoelectric effect of the piezoelectric layer of the piezoelectric element so as to discharge the ink out of the pressure chamber, wherein
• the first electrode layer of the piezoelectric element 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.

An ink jet head, comprising:

• a piezoelectric element in which a first electrode layer, an orientation control layer, a piezoelectric layer and a second electrode layer are layered in this order;
• a vibration layer provided on one surface of the piezoelectric element that is closer to the first electrode layer;
• and a pressure chamber member bonded to one surface of the vibration layer that is away from the piezoelectric element and including a pressure chamber for storing ink therein, in which the vibration layer is displaced in a thickness direction by a piezoelectric effect of the piezoelectric layer of the piezoelectric element so as to discharge the ink out of the pressure chamber, wherein
• the first electrode layer of the piezoelectric element 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.

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.

A method for manufacturing a piezoelectric element, comprising the steps of:

• forming a first electrode layer made of a noble metal containing titanium or titanium oxide on a substrate by a sputtering method;
• forming an orientation control layer made of a cubic or tetragonal perovskite oxide on the first electrode layer by a sputtering method;
• forming a piezoelectric layer made of a rhombohedral or tetragonal perovskite oxide on the orientation control layer by a sputtering method;
• and forming a second electrode layer on the piezoelectric layer, wherein
• the step of forming the orientation control layer includes a step of using titanium or titanium oxide which exists on one surface of the first electrode layer that is closer to the orientation control layer as a nucleus to perform crystal growth over the titanium or titanium oxide such that the orientation control layer is preferentially oriented along the (100) or (001) plane, and
• the step of forming the piezoelectric layer includes a step of preferentially orienting the piezoelectric layer along the (001) plane by the orientation control layer.

A method for manufacturing an ink jet head, the ink jet head including a piezoelectric element in which a first electrode layer, an orientation control layer, a piezoelectric layer and a second electrode layer are layered in this order, in which a vibration layer is displaced in a thickness direction by a piezoelectric effect of the piezoelectric layer of the piezoelectric element so as to discharge ink out of a pressure chamber, the method comprising the steps of:

• forming the first electrode layer made of a noble metal containing titanium or titanium oxide on a substrate by a sputtering method;
• forming the orientation control layer made of a cubic or tetragonal perovskite oxide on the first electrode layer by a sputtering method;
• forming the piezoelectric layer made of a rhombohedral or tetragonal perovskite oxide by a sputtering method;
• forming the second electrode layer on the piezoelectric layer;
• forming the vibration layer on the second electrode layer;
• bonding a pressure chamber member for forming the pressure chamber on one surface of the vibration layer that is away from the second electrode layer;
• and
• removing the substrate after the bonding step, wherein
• the step of forming the orientation control layer includes a step of using titanium or titanium oxide which exists on one surface of the first electrode layer that is closer to the orientation control layer as a nucleus to perform crystal growth over the titanium or titanium oxide such that the orientation control layer is preferentially oriented along the (100) or (001) plane, and
• the step of forming the piezoelectric layer includes a step of preferentially orienting the piezoelectric layer along the (001) plane by the orientation control layer.

A method for manufacturing an ink jet head, the ink jet head including a piezoelectric element in which a first electrode layer, an orientation control layer, a piezoelectric layer and a second electrode layer are layered in this order, in which a vibration layer is displaced in a thickness direction by a piezoelectric effect of the piezoelectric layer of the piezoelectric element so as to discharge ink out of a pressure chamber, the method comprising the steps of:

• forming the vibration layer on a pressure chamber substrate for forming the pressure chamber;
• forming the first electrode layer made of a noble metal containing titanium or titanium oxide on the vibration layer by a sputtering method;
• forming the orientation control layer made of a cubic or tetragonal perovskite oxide on the first electrode layer by a sputtering method;
• forming the piezoelectric layer made of a rhombohedral or tetragonal perovskite oxide by a sputtering method;
• forming the second electrode layer on the piezoelectric layer;
• and
• forming the pressure chamber in the pressure chamber substrate, wherein
• the step of forming the orientation control layer includes a step of using titanium or titanium oxide which exists on one surface of the first electrode layer that is closer to the orientation control layer as a nucleus to perform crystal growth over the titanium or titanium oxide such that the orientation control layer is preferentially oriented along the (100) or (001) plane, and
• the step of forming the piezoelectric layer includes a step of preferentially orienting the piezoelectric layer along the (001) plane by the orientation control layer.

A method for manufacturing an angular velocity sensor, the 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, the method comprising the steps of:

• forming the first electrode layer made of a noble metal containing titanium or titanium oxide on a substrate by a sputtering method;
• forming the orientation control layer made of a cubic or tetragonal perovskite oxide on the first electrode layer by a sputtering method;
• forming the piezoelectric layer made of a rhombohedral or tetragonal perovskite oxide on the orientation control layer by a sputtering method;
• forming the second electrode layer on the piezoelectric layer;
• patterning the second electrode layer so as to form the driving electrode and the detection electrode;
• patterning the piezoelectric layer, the orientation control layer and the first electrode layer;
• and
• patterning the substrate so as to form the fixed portion and the vibrating portions, wherein
• the step of forming the orientation control layer includes a step of using titanium or titanium oxide which exists on one surface of the first electrode layer that is closer to the orientation control layer as a nucleus to perform crystal growth over the titanium or titanium oxide such that the orientation control layer is preferentially oriented along the (100) or (001) plane, and
• the step of forming the piezoelectric layer includes a step of preferentially orienting the piezoelectric layer along the (001) plane by the orientation control layer.

An ink jet recording apparatus, comprising an ink jet head, the ink jet head including:

• a piezoelectric element in which a first electrode layer, an orientation control layer, a piezoelectric layer and a second electrode layer are layered in this order;
• a vibration layer provided on one surface of the piezoelectric element that is closer to the second electrode layer;
• and a pressure chamber member bonded to one surface of the vibration layer that is away from the piezoelectric element and including a pressure chamber for storing ink therein, the ink jet head being capable of being relatively moved with respect to a recording medium, in which while the ink jet head is moved with respect to the recording medium, the vibration layer is displaced in a thickness direction by a piezoelectric effect of the piezoelectric layer of the piezoelectric element in the ink jet head so as to discharge the ink out of the pressure chamber through a nozzle hole communicated to the pressure chamber onto the recording medium, thereby recording information, wherein:
• the first electrode layer of the piezoelectric element of the ink jet head 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.

An ink jet recording apparatus, comprising an ink jet head, the ink jet head including:

• a piezoelectric element in which a first electrode layer, an orientation control layer, a piezoelectric layer and a second electrode layer are layered in this order;
• a vibration layer provided on one surface of the piezoelectric element that is closer to the first electrode layer;
• and a pressure chamber member bonded to one surface of the vibration layer that is away from the piezoelectric element and including a pressure chamber for storing ink therein, the ink jet head being capable of being relatively moved with respect to a recording medium, in which while the ink jet head is moved with respect to the recording medium, the vibration layer is displaced in a thickness direction by a piezoelectric effect of the piezoelectric layer of the piezoelectric element in the ink jet head so as to discharge the ink out of the pressure chamber through a nozzle hole communicated to the pressure chamber onto the recording medium, thereby recording information, wherein:
• the first electrode layer of the piezoelectric element of the ink jet head 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.