| 摘要 |
PROBLEM TO BE SOLVED: To favorably perform etching without leaving a residue even in a piezoelectric film having a pyrochlore layer.SOLUTION: An etchant for etching a piezoelectric film 14 is formed by growing, on a lower electrode 12 formed on a substrate 10, a thin film with a perovskite structure to have a columnar structure and has a pyrochlore layer at an interface between the lower electrode and the piezoelectric film. The etchant contains at least a nitric acid and a hydrofluoric acid based chemical containing at least one of a buffered hydrofluoric acid (BHF), hydrogen fluoride (HF), and a diluted hydrofluoric acid (DHF), while the weight concentration of a hydrochloric acid is less than 10%, and the weight ratio (hydrochloric acid/nitric acid) between the hydrochloric acid and the nitric acid is 1/4 or less. In a method for manufacturing a piezoelectric element, etching is performed using the etchant. |
