Angular velocity sensor and manufacturing method thereof
A substrate is made of single crystal silicon and having a tuning folk shape. The substrate includes plural arms extending in parallel with each other and a joint section for connecting respecting ends of the arms with each other. An angular velocity sensor includes a barrier layer containing silicon oxide provided on each of the arms of the substrate, a first adhesion layer containing titanium provided on the barrier layer a first electrode layer containing at least one of titanium and titanium oxide provided on the first adhesion layer, an orientation control layer provided on the first electrode layer, a piezoelectric layer provided on the orientation control layer, a second adhesion layer provided on the piezoelectric layer, and a second electrode layer provided on the second adhesion layer. This angular velocity sensor has a small size and stable characteristics.
1 . An angular velocity sensor comprising:
a substrate made of single crystal silicon and having a tuning folk shape, the substrate including
a plurality of arms extending in parallel with each other, and
a joint section for connecting respecting ends of the arms with each other;
a barrier layer provided on each of the plurality of arms of the substrate, the barrier layer containing silicon oxide;
a first adhesion layer provided on the barrier layer, the first adhesion layer containing titanium;
a first electrode layer provided on the first adhesion layer, the first electrode layer containing at least one of titanium and titanium oxide;
an orientation control layer provided on the first electrode layer;
a piezoelectric layer provided on the orientation control layer;
a second adhesion layer provided on the piezoelectric layer; and
a second electrode layer provided on the second adhesion layer.
2 . The angular velocity sensor of claim 1 , wherein the orientation control layer comprises dielectric oxide material containing Pb and Ti.
3 . The angular velocity sensor of claim 1 , wherein the orientation control layer comprises lead titanate containing at least one of La and Mg.
4 . The angular velocity sensor of claim 1 , wherein the piezoelectric layer comprises slead zirconate titanate.
5 . A method of manufacturing an angular velocity sensor, comprising:
providing a substrate made of single crystal silicon and having a tuning folk shape, the substrate including a plurality of arms and a joint section for connecting respecting ends of the arms with each other, the plurality of arms extending in parallel with each other;
forming a barrier layer containing silicon oxide by oxidizing a surface of the plurality of the arms of the substrate;
forming a first adhesion layer containing titanium on the barrier layer by sputtering;
forming a first electrode layer containing platinum and at least one of titanium and titanium oxide on the first adhesion layer by sputtering;
forming an orientation control layer on the first electrode layer by sputtering;
forming a piezoelectric layer on the orientation control layer by sputtering;
forming a second adhesion layer on the piezoelectric layer by sputtering or vacuum deposition; and
forming a second electrode layer on the second adhesion layer by sputtering or vacuum deposition.
6 . The method of claim 5 , wherein said forming the barrier layer comprises thermally oxidizing a surface of the substrate.
7 . The method of claim 5 , wherein the orientation control layer comprises dielectric oxide material containing Pb and Ti.
8 . The method of claim 5 , wherein the orientation control layer comprises lead titanate containing at least one of La and Mg.
9 . The method of claim 5 , wherein the piezoelectric layer comprises lead zirconate titanate.