Patent ID: 7157288

Claim:
A method of producing a ferroelectric capacitor, comprising: preparing a semiconductor substrate; forming a first insulating layer on the semiconductor substrate; laminating sequentially a metal layer, a first conductive layer, a ferroelectric layer, and a second conductive layer on the first insulating layer to form a capacitor forming laminated layer; forming an etching mask forming layer formed of strontium tantalate or strontium niobate on the capacitor forming laminated layer; forming a silicon oxide layer mask on the etching mask forming layer covering a ferroelectric capacitor forming area; forming an etching mask through first wet etching of the etching mask forming layer with the silicon oxide layer mask in a mixture of nitric acid, fluorinated acid, and acetic acid; and forming a lamination having a barrier metal, a lower electrode, a ferroelectric layer, and an upper electrode through dry etching of the capacitor forming laminated layer with the etching mask.