Patent ID: 7977853

Claim:
A piezoelectric device comprising: a substrate having a surface; an electrode formed over said surface of the substrate; and a piezoelectric film formed over said surface of the substrate through said electrode by vapor phase deposition using plasma; wherein said piezoelectric film is a columnar film constituted by a plurality of columnar crystals which are composed of one or more perovskite oxides and inevitable impurities, and extend nonparallel to said surface of the substrate, each of the one or more perovskite oxides is expressed by a compositional formula Pb(Ti x , Zr y , M z )O 3 , M in the compositional formula represents one or more of metal elements Sn, Nb, Ta, Mo, W, Ir, Os, Pd, Pt, Re, Mn, Co, Ni, V, and Fe, 0<x<1, 0<y<1, 0≦z<1, and x+y+z=1, said plurality of columnar crystals have end faces at a surface of said columnar film, and 20% or more of the plurality of columnar crystals have end faces with diameters of minimum circumscribed circles not exceeding 100 nm, and 5% or more of the plurality of columnar crystals have end faces with diameters of minimum circumscribed circles of 500 nm or greater, and said columnar film has an arithmetic average surface roughness of 10 nm or smaller.