Ferroelectric thin film, method of manufacturing the same, ferroelectric memory device and ferroelectric piezoelectric device

Abstract

A ferroelectric thin film formed of a highly oriented polycrystal in which 180° domains and 90° domains arrange at a constant angle to an applied electric field direction in a thin film plane and reversely rotate in a predetermined electric field.

1 . A ferroelectric thin film formed of crystals in which directions of polarization axes are inconsistent with an applied electric field direction in a crystal system.  
   
   
       2 . A ferroelectric thin film formed of crystals in which directions of 180° domains are inconsistent with an applied electric field direction in a crystal system.  
   
   
       3 . A ferroelectric thin film formed of crystals in which directions of  900  domains are inconsistent with a direction perpendicular to an applied electric field direction in a crystal system.  
   
   
       4 . The ferroelectric thin film as defined in  claim 1 , wherein the 180° domains are arranged at a constant angle to the applied electric field direction.  
   
   
       5 . The ferroelectric thin film as defined in  claim 1 , wherein the 90° domains are arranged at a constant angle to the applied electric field direction.  
   
   
       6 . The ferroelectric thin film as defined in  claim 1 , wherein the 180° domains reversely rotate in a predetermined electric field with respect to the applied electric field direction and a ferroelectric thin film plane.  
   
   
       7 . The ferroelectric thin film as defined in  claim 1 , wherein the 90° domains reversely rotate in a predetermined electric field with respect to the applied electric field direction and a ferroelectric thin film plane.  
   
   
       8 . The ferroelectric thin film as defined in  claim 1 , wherein polarization is arranged at a constant angle to the applied electric field direction have the same polarization in the same applied electric field.  
   
   
       9 . The ferroelectric thin film as defined in  claim 1 , formed of a polycrystal highly oriented in the applied electric field direction in a ferroelectric thin film plane.  
   
   
       10 . The ferroelectric thin film as defined in  claim 1 , wherein a polarization axis distribution exhibits no anisotropy with respect to the applied electric field direction in a ferroelectric thin film plane.  
   
   
       11 . The ferroelectric thin film as defined in  claim 1 , using: a tetragonal Pb(Zr,Ti)O 3  ferroelectric which is ( 111 )-oriented along the applied electric field direction with respect to a ferroelectric thin film plane.  
   
   
       12 . The ferroelectric thin film as defined in  claim 1 , using: a rhombohedral Pb(Zr,Ti)O 3  ferroelectric which is ( 001 )-oriented along the applied electric field direction with respect to a ferroelectric thin film plane.  
   
   
       13 . The ferroelectric thin film as defined in  claim 1 , using: a bismuth-layer-structured ferroelectric which is ( 111 ) or ( 110 )-oriented along the applied electric field direction with respect to a ferroelectric thin film plane.  
   
   
       14 . The ferroelectric thin film as defined in  claim 1 , using: an SrBi 2 Ta 2 O 9  ferroelectric which is ( 115 ), ( 111 ), or ( 110 )-oriented along the applied electric field direction with respect to a ferroelectric thin film plane.  
   
   
       15 . The ferroelectric thin film as defined in  claim 1 , using: a Bi 4 T 3 O 12  ferroelectric which is ( 117 ), ( 111 ), ( 107 ), or ( 317 )-oriented along the applied electric field direction with respect to a ferroelectric thin film plane.  
   
   
       16 . The ferroelectric thin film as defined in  claim 11 , using a ( 111 )-oriented platinum group metal electrode with a full width half maximum of 2° or less.  
   
   
       17 . The ferroelectric thin film as defined in  claim 12 , using a ( 001 )-oriented platinum group metal electrode with a full width half maximum of 2° or less.  
   
   
       18 . The ferroelectric thin film as defined in  claim 13 , using a ( 111 )-oriented platinum group metal electrode with a full width half maximum of 2° or less.  
   
   
       19 . The ferroelectric thin film as defined in  claim 14 , using a ( 111 )-oriented platinum group metal electrode with a full width half maximum of 2° or less.  
   
   
       20 . The ferroelectric thin film as defined in  claim 15 , using a ( 111 )-oriented platinum group metal electrode with a full width half maximum of 2° or less.  
   
   
       21 . The ferroelectric thin film as defined in  claim 13 , using a ( 110 )-oriented platinum group metal electrode with a full width half maximum of 2° or less.  
   
   
       22 . The ferroelectric thin film as defined in  claim 14 , using a ( 110 )-oriented platinum group metal electrode with a full width half maximum of 2° or less.  
   
   
       23 . The ferroelectric thin film as defined in  claim 15 , using a ( 110 )-oriented platinum group metal electrode with a full width half maximum of 2° or less.  
   
   
       24 . The ferroelectric thin film as defined in  claim 16 , using an alloy electrode of lead and platinum group metal.  
   
   
       25 . The ferroelectric thin film as defined in  claim 1 , formed by using a mixed solution of a sol-gel solution and an metal organic decomposition solution.  
   
   
       26 . The ferroelectric thin film as defined in  claim 1 , comprising silicon, or silicon and germanium in elements of ferroelectric.  
   
   
       27 . A method of manufacturing the ferroelectric thin film as defined in  claim 1 , comprising: performing crystallization by rapid heating in an oxidizing gas atmosphere at a pressure less than 10 atmospheres.  
   
   
       28 . A ferroelectric memory device using the ferroelectric thin film as defined in  claim 1 .  
   
   
       29 . A ferroelectric piezoelectric device using the ferroelectric thin film as defined in  claim 1.