Patent ID: 8733905

Claim:
A process for producing a piezoelectric device comprising: a substrate; and a laminated film being formed above said substrate, and including, a lower electrode layer, a piezoelectric layer formed by sputtering on said lower electrode layer, and an upper electrode layer formed on said piezoelectric layer; wherein said lower electrode layer is a metal electrode layer containing as one or more main components one or more of nonnoble metals and nonnoble alloys, said process comprising the steps of: (a) forming a first film for said lower electrode layer; (b) patterning said first film; (c) forming a second film for said piezoelectric layer; and (d) patterning said second film, wherein said lower electrode layer is formed by vapor phase epitaxy, said lower electrode layer is patterned by use of wet etching, said piezoelectric layer is foamed at 400° C. to 600° C., and said piezoelectric layer is formed by vapor phase epitaxy using plasma under a condition that the difference between a floating potential and a plasma potential in plasma generated during formation of the piezoelectric layer is 10 to 35 V.