Patent ID: 9444032
Filing Date: 2016-09-13
CPC Classification: G02B,G02F,H01L,Y10T

Claim Text:
1. A piezoelectric element comprising: a substrate having a first surface with a predetermined orientation; a lower electrode layered on the first surface of the substrate; a piezoelectric thin film layered on the lower electrode and having a piezoelectric body; and an upper electrode layered on the piezoelectric thin film, the piezoelectric thin film being deformed by impressing a voltage between the lower electrode and the upper electrode, wherein the piezoelectric thin film is epitaxially grown on the lower electrode using a physical vapor deposition or a chemical vapor deposition at a temperature higher than or equal to 650 degrees Celsius, such that the arithmetic average coarseness Ra of the piezoelectric thin film is approximately equal to 20 nm.