Laminated substrate having piezoelectric film, element having piezoelectric film and method for manufacturing this laminated substrate

Abstract

There is provided a laminated substrate having a piezoelectric film, including: a substrate; and a piezoelectric film provided on the substrate interposing a base film, wherein the piezoelectric film has an alkali niobium oxide based perovskite structure represented by a composition formula of (K 1-x Na x )NbO 3 (0<x<1) and preferentially oriented in (001) plane direction, and a sound speed of the piezoelectric film is 5100 m/s or more.

1 . A laminated substrate having a piezoelectric film, comprising:
 a substrate; and   a piezoelectric film on the substrate interposing a base film,   wherein a sound speed of the piezoelectric film is 5100 m/s or more, and an absolute value |d 31 | of a piezoelectric constant of the piezoelectric film is 90 pm/V or more.   
     
     
         2 . The laminated substrate having a piezoelectric film according to  claim 1 , wherein the piezoelectric film has an alkali niobium oxide based perovskite structure represented by a composition formula of (K 1 - x Na x )NbO 3 , wherein 0<x<1, and preferentially oriented in (001) plane direction. 
     
     
         3 . The laminated substrate having a piezoelectric film according to  claim 1 , wherein the piezoelectric film contains an element of Cu, Mn, Li, Ta, or Sb in a range of 5 at% or less. 
     
     
         4 . A piezoelectric film element comprising the substrate having a piezoelectric film according to  claim 1  and an electrode film provided on the piezoelectric film. 
     
     
         5 . The piezoelectric film element according to  claim 4 , wherein the piezoelectric film has an alkali niobium oxide based perovskite structure represented by a composition formula of (K 1 - x Na x )NbO 3 , where 0<x<1, and preferentially oriented in (001) plane direction. 
     
     
         6 . The piezoelectric film element according to  claim 4 , wherein the piezoelectric film contains an element of Cu, Mn, Li, Ta, or Sb in a range of 5 at% or less. 
     
     
         7 . A method for manufacturing the laminated substrate having a piezoelectric film according to  claim 1 , the method comprising:
 forming a piezoelectric film on a substrate interposing a base film, wherein a sound speed of the piezoelectric film is 5100 m/s or more, and an absolute value |d 31 | of a piezoelectric constant of the piezoelectric film is 90 pm/V or more.   
     
     
         8 . The method according to  claim 7 , wherein the piezoelectric film has an alkali niobium oxide based perovskite structure represented by a composition formula of (K 1-x Na x )NbO 3 , where 0<x<1, and preferentially oriented in (001) plane direction. 
     
     
         9 . The method according to  claim 7 , wherein the piezoelectric film contains an element of Cu, Mn, Li, Ta, or Sb in a range of 5 at% or less.