Patent ID: 9299911
Filing Date: 2016-03-29
CPC Classification: H01L

Claim Text:
1. A piezoelectric thin-film multilayer body comprising: a substrate; an adhesive layer on the substrate; a lower electrode layer on the adhesive layer; and a lead-free piezoelectric thin-film layer on the lower electrode layer, wherein the lead-free piezoelectric thin-film layer is composed of lithium potassium sodium niobate (composition formula (Na wherein a maximum height Rz of a roughness of an adhesive-layer-facing surface of the substrate is 2 nm or less, wherein the adhesive layer is composed of a non-crystalline oxide of a Group 4 element or a non-crystalline oxide of a Group 5 element, and wherein the adhesive layer has a thickness of 1 nm or more and 2 nm or less and is equal to or more than the maximum height Rz of the roughness of the surface of the substrate.