| 摘要 |
A method for manufacturing a piezoelectric element, in which a ferroelectric film is processed in an appropriate shape by plasma etching, is provided. A metal mask made of a metal thin film which is hard to be etched by oxygen gas is placed on an object to be processed formed by laminating a lower electrode layer and a ferroelectric film on a substrate in this order. An etching gas containing a mixture gas of the oxygen gas and a reactive gas including fluorine in a chemical structure is turned into plasma and is brought into contact with the metal mask and the object to be processed. An AC voltage is applied to an electrode disposed beneath the object to be processed so that ions in the plasma are caused to enter the object to be processed to perform anisotropic etching on the ferroelectric film. |
