METHOD FOR MANUFACTURING SUBSTRATE WITH PIEZOELECTRIC THIN FILM, AND METHOD FOR MANUFACTURING PIEZOELECTRIC THIN FILM ELEMENT

摘要

PROBLEM TO BE SOLVED: To provide: a method for manufacturing a substrate with a piezoelectric thin film, capable of wet etching a lead-free piezoelectric thin film in a simple manner and at a low cost to perform fine processing; and a method for manufacturing a piezoelectric thin film element.SOLUTION: In an embodiment of the present invention, there is provided a method for manufacturing a substrate 1 with a piezoelectric thin film, including the steps of: forming a lower electrode 11 on a substrate 10; forming a piezoelectric thin film 12 having an alkali niobium oxide-based perovskite structure represented by a composition formula of (KNa)NbO, on the lower electrode 11; and forming an organic resist mask 14 on the piezoelectric thin film to apply wet etching to the piezoelectric thin film 12 using an etchant containing a hydrofluoric acid and a hydrochloric acid or sulfuric acid.