Method for manufacturing piezoelectric element and piezoelectric element manufactured using same

摘要

A stress relaxing layer L22 composed of MgO is formed on the upper surface of a substrate layer L1 in order to alleviate stress acting on a piezoelectric layer L3, the stress relaxing layer L22 is removed while leaving behind a region D1 where the piezoelectric layer L3 is to be formed, and the single crystal piezoelectric layer L3 is formed on the upper surface of the stress relaxing layer L22. As a result, the stress relaxing layer L22 in a region D2 where the piezoelectric layer L3 is not to be formed is preliminarily removed, the region D1 where the piezoelectric layer L3 is to be formed is reduced in size, and stress acting on the piezoelectric layer L3 attributable to the difference in lattice constant between the stress relaxing layer L22 and the piezoelectric layer L3 and thermal expansion is alleviated, thereby enabling favorable single crystallization of the piezoelectric layer L3.

主权项

1. A piezoelectric element comprising:
a substrate layer; an intermediate layer formed on an upper surface of the substrate layer in order to alleviate stress acting on a piezoelectric layer during deposition of the piezoelectric layer such that a portion of the intermediate layer is removed except for a region where the piezoelectric layer is to be formed; and a piezoelectric layer formed on an upper surface of the intermediate layer, wherein the substrate layer has an oxide film layer formed on the surface thereof, wherein the intermediate layer includes a lower electrode layer formed on an upper surface of the oxide film layer and a stress relaxing layer formed in a prescribed region on an upper surface of the lower electrode layer, wherein the piezoelectric layer is formed on an upper surface of the stress relaxing layer, wherein the piezoelectric element further includes an upper electrode layer formed on the upper surface of the piezoelectric layer, and wherein the lattice constant of the stress relaxing layer has a value that is closer to the lattice constant of the piezoelectric layer than the lattice constant of the lower electrode layer.