Piezoelectric Element, Liquid Jetting Head, and Method for Manufacturing Thereof

Abstract

The present invention provides a piezoelectric element having consistently high piezoelectric characteristics, and a liquid jetting head in which this element is used. A bottom electrode 42 (which contains Ir), a Ti layer of no less than 4 nm and no more than 6 nm, a piezoelectric thin film 43 , and a top electrode 44 are sequentially layered on a ZrO 2 film 32 . The piezoelectric thin film 43 has the degree of orientation in the 100 plane, as measured by the X-ray diffraction wide angle technique, is 70% or greater, the degree of orientation in the 110 plane is 10% or less, and the degree of orientation in the 111 plane constitutes the remaining balance. Such piezoelectric thin film 43 can be obtained stably with good reproducibility by keeping the humidity of the environment for forming the piezoelectric thin film at 30% Rh or less.

1 . A piezoelectric element comprising: 
 a bottom electrode;    a piezoelectric thin film formed on the bottom electrode; and    a top electrode formed on the piezoelectric thin film, wherein the piezoelectric thin film has a rhombohedral structure and a degree of orientation in the  100  plane of 70% or greater, as measured by the X-ray diffraction wide angle technique.    
     
     
         2 . The piezoelectric element according to  claim 1 , wherein the piezoelectric thin film has a degree of orientation in the  110  plane of 10% or less, with the balance constituting the orientation in the  111  plane, as measured by the X-ray diffraction wide angle technique.  
     
     
         3 . A liquid jetting head comprising: 
 a drive element wherein said drive element includes a piezoelectric element comprising a bottom electrode, a piezoelectric thin film formed on the bottom electrode, and a top electrode formed on the piezoelectric thin film, wherein the piezoelectric thin film has a rhombohedral structure and a degree of orientation in the  100  plane of 70% or greater, as measured by the X-ray diffraction wide angle technique.    
     
     
         4 - 7 . (canceled)  
     
     
         8 . A system for manufacturing a piezoelectric element, comprising: 
 a manufacturing apparatus capable of performing a step for forming a piezoelectric thin film on a bottom electrode; and    a humidity-adjusting apparatus for adjusting the environment for forming the piezoelectric thin film to a humidity of 30% Rh or less.    
     
     
         9 . The liquid jetting head according to  claim 3 , wherein the piezoelectric thin film has a degree of orientation in the  110  plane of 10% or less, with the balance constituting the orientation in the  111  plane, as measured by the X-ray diffraction wide angle technique.