Ferroelectric thin film element and its manufacturing method, thin film capacitor and piezoelectric actuator using same
View Patent ↗In a manufacturing method for a piezoelectric actuator a first electrode layer is formed on substrate, a ferroelectric thin film is formed on the first electrode layer, and an inorganic protective layer 4 is formed on the ferroelectric thin film. Then, the inorganic protective layer 4 and the ferroelectric thin film are heat-treated under an oxygen containing atmosphere, and a second electrode layer is formed on an oxidation diffusion layer, wherein the oxidation diffusion layer is formed on a surface of the ferroelectric thin film as a result of component diffusion of the ferroelectric thin film and oxidation of the inorganic protective layer 4 due to the heat treatment. By using this method, it is possible to improve ferroelectricity without deterioration or cracking of a surface of the ferroelectric thin film.
1. A method of manufacturing a ferroelectric thin film element, comprising:
forming a first electrode layer on a substrate;
forming a ferroelectric thin film on said first electrode layer;
forming an inorganic protective layer on said ferroelectric thin film; and
heat treating said inorganic protective layer and said ferroelectric thin film under an atmosphere containing oxygen, thereby causing said inorganic protective layer to be oxidized and a part of a component of said ferroelectric thin film to be diffused, such that an oxidation diffusion layer is formed on which a second electrode layer is to be formed.
2. The method of manufacturing a ferroelectric thin film element of claim 1 ,
wherein said inorganic protective layer contains at least one of components of said ferroelectric thin film.
3. The method of manufacturing a ferroelectric thin film element of claim 2 ,
wherein said ferroelectric thin film contains at least one of titanium and zirconium as a component element; and
said inorganic protective layer contains at least one of titanium and zirconium.
4. The method of manufacturing a ferroelectric thin film element of claim 3 ,
wherein said ferroelectric thin film further contains lead as a component element.
5. The method of manufacturing a ferroelectric thin film element of claim 4 ,
wherein said substrate is a magnesium oxide mono-crystalline substrate; and
said first electrode layer is a platinum plate.
6. The method of manufacturing a ferroelectric thin film element of claim 1 ,
including forming said first electrode layer and said ferroelectric thin film by sputtering.
7. The method of manufacturing a ferroelectric thin film element of claim 1 , further comprising:
forming a second electrode layer on said oxidation diffusion layer.
8. The method of manufacturing a ferroelectric thin film element of claim 7 ,
wherein said inorganic protective layer contains at least one of components of said ferroelectric thin film.
9. The method of manufacturing a ferroelectric thin film element of claim 8 ,
wherein said ferroelectric thin film contains at least one of titanium and zirconium as a component element; and
said inorganic protective layer contains at least one of titanium and zirconium.
10. The method of manufacturing a ferroelectric thin film element of claim 9 ,
wherein said ferroelectric thin film further contains lead as a component element.
11. The method of manufacturing a ferroelectric thin film element of claim 10 ,
wherein said substrate is a magnesium oxide mono-crystalline substrate; and
said first electrode layer is a platinum plate.
12. The method of manufacturing a ferroelectric thin film element of claim 8 ,
including forming said first electrode layer and said ferroelectric thin film by sputtering.
13. The method of manufacturing a ferroelectric thin film element of claim 7 , wherein said inorganic protective layer comprises a metal protective film.
14. The method of manufacturing a ferroelectric thin film element of claim 13 ,
wherein said inorganic protective layer contains at least one of components of said ferroelectric thin film.
15. The method of manufacturing a ferroelectric thin film element of claim 14 ,
wherein said ferroelectric thin film contains at least one of titanium and zirconium as a component element; and
said inorganic protective layer contains at least one of titanium and zirconium.
16. The method of manufacturing a ferroelectric thin film element of claim 15 ,
wherein said ferroelectric thin film further contains lead as a component element.
17. The method of manufacturing a ferroelectric thin film element of claim 16 ,
wherein said substrate is a magnesium oxide mono-crystalline substrate; and
said first electrode layer is a platinum plate.
18. The method of manufacturing a ferroelectric thin film element of claim 14 ,
including forming said first electrode layer and said ferroelectric thin film by sputtering.
19. The method of manufacturing a ferroelectric thin film element of claim 1 , wherein said inorganic protective layer comprises a metal protective film.
20. The method of manufacturing a ferroelectric thin film element of claim 19 ,
wherein said ferroelectric thin film contains at least one of titanium and zirconium as a component element; and
said inorganic protective layer contains at least one of titanium and zirconium.