Ferroelectric thin film element and its manufacturing method, thin film capacitor and piezoelectric actuator using same

A thin film capacitor that is to use a ferroelectric thin film element,

• wherein said ferroelectric thin film element comprises:
• a first electrode layer formed on a substrate;
• a ferroelectric thin film formed on said first electrode layer such that said first electrode layer is between said substrate and said ferroelectric thin film;
• an oxidation diffusion layer formed on said ferroelectric thin film, wherein said oxidation diffusion layer is formed by an oxidized inorganic protective layer and a part of a component of said ferroelectric thin layer;
• and
• a second electrode layer formed on said oxidation diffusion layer such that said oxidation diffusion layer is between said ferroelectric thin film and said second electrode layer.

A piezoelectric actuator, that is to use a ferroelectric thin film element,

• wherein a piezoelectric element of the piezoelectric actuator comprises:
• a first electrode layer formed on a substrate;
• a ferroelectric thin film formed on said first electrode layer such that said first electrode layer is between said substrate and said ferroelectric thin film;
• an oxidation diffusion layer formed on said ferroelectric thin film, wherein said oxidation diffusion layer is formed by an oxidized inorganic protective layer and a part of a component of said ferroelectric thin layer;
• and
• a second electrode layer formed on said oxidation diffusion layer such that said oxidation diffusion layer is between said ferroelectric thin film and said second electrode layer,
• wherein a portion of said substrate in an area corresponding to said ferroelectric thin film is removed.

A piezoelectric actuator that is to use a laminated pair of ferroelectric thin film elements,

• wherein each of said ferroelectric thin film elements of the piezoelectric actuator comprises:
• a first electrode layer formed on a substrate;
• a ferroelectric thin film formed on said first electrode layer such that said first electrode layer is between said substrate and said ferroelectric thin film;
• an oxidation diffusion layer formed on said ferroelectric thin film, wherein said oxidation diffusion layer is formed by an oxidized inorganic protective layer and a part of a component of said ferroelectric thin layer;
• a second electrode layer formed on said oxidation diffusion layer such that said oxidation diffusion layer is between said ferroelectric thin film and said second electrode layer;
• and
• connection wiring by which said first electrode layer and said second electrode layer of each of said ferroelectric thin film elements are electrically connected to each other;
• wherein said laminated pair is structured by using a bonding agent to bond together said second electrodes of said ferroelectric thin film elements, and
• wherein a portion of said substrate in an area corresponding to said ferroelectric thin film is removed.