Ferroelectric memory and electronic apparatus
AssigneeSeiko Epson Corporation
InventorsTakamitsu Higuchi, Setsuya Iwashita, Hiromu Miyazawa
Life of this patent
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Abstract
In case capacitor-type ferroelectric memory is formed by using SrB2Ta2O9 having superior fatigue resistance for ferroelectric layer, non-orientation layer is inferior in angularity, and SBT of orientation layer is subject to be oriented to c-axis orientation, polarization moment of a-axis direction was not effectively used, on Si single crystal substrate, a buffer layer and a bottom electrode layer composed of conductive oxide having perovskite structure are grown in epitaxially, furthermore the epitaxial growth of ferroelectric layer composed of SBT is performed with slanting c-axis to the substrate by 45 to 55 degrees.
Claims12
A ferroelectric memory comprising:
- an Si single crystal substrate;
- a buffer layer composed of metal oxide on the Si single crystal substrate;
- a bottom electrode layer including either a conductive oxide having a perovskite structure or a metal platinum Pt on the buffer layer;
- a ferroelectric layer composed of SrBi2Ta2O9 or Sr1−xBi2+x(Ta1−yNby)2O9(0≦x≦0.2, 0≦y≦1) having a layered perovskite structure on the bottom electrode layer;
- and
- a top electrode layer on the ferroelectric layers wherein the ferroelectric layer is in (116)-orientation in an orthorhombic system or in (117)-orientation.
A ferroelectric memory comprising:
- an Si single crystal substrate;
- a buffer layer composed of metal oxide on the Si single crystal substrate;
- a bottom electrode layer including either a conductive oxide having a perovskite structure or a metal platinum Pt on the buffer layer;
- a ferroelectric layer composed of SrBi2Ta2O9 or Sr1−xBi2+x(Ta1−yNby)2O9(0≦x≦0.2, 0≦y≦1) having a layered perovskite structure on the bottom electrode layer;
- and
- a top electrode layer on the ferroelectric layer,
- wherein the ferroelectric layer is in (103)-orientation in an orthorhombic system or in (104)-orientation.
Dependencies are inferred from the claim text.