Cubic metal oxide thin film epitaxially grown on silicon
AssigneeBell Communications Research, Inc.
InventorRamamoorthy Ramesh
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Abstract
A method of forming crystalline metal oxide thin films on silicon and the resultant structure. A crystalline buffer layer (10) of yttria-stabilized zirconia is deposited on a silicon substrate (12). A thin template layer (10) of an anisotropic perovskite such as bismuth titanate or yttria barium copper oxide is deposited on the template layer under conditions favoring c-axis oriented growth. A nominally cubic metal-oxide layer (16) is deposited on the template layer which facilitates its singly crystalline growth. The metal oxide, often a nominally cubic perovskite, may be a conductive electrode, a ferroelectric, a non-hysteretic dielectric, a piezoelectric, or other class of material.
Claims17
A silicon/metal-oxide heterostructure, comprising:
- a silicon substrate;
- a buffer layer formed on said silicon substrate;
- a template layer comprising an anisotropic perovskite formed on said buffer layer, said buffer layer allowing said template layer to be formed substantially c-axis oriented;
- and
- a nominally cubic metal-oxide layer formed on said template layer.
A ferroelectric memory element, comprising:
- a singly crystalline silicon substrate;
- a buffer layer formed on said substrate;
- a singly crystalline film comprising a conductive metal oxide formed on said buffer layer, said buffer layer promoting said metal oxide to form as said singly crystalline film;
- and
- a ferroelectric layer epitaxially formed on said crystalline film.
A method of forming a silicon/metal-oxide heterostructure, comprising the steps of:
- depositing upon a crystalline silicon substrate a first layer of a buffer material;
- depositing upon said first layer a second layer comprising an anisotropic perovskite under growth conditions favoring c-axis oriented growth of said anisotropic perovskite, said buffer material facilitating growth of said second layer as a substantially crystalline layer;
- and
- depositing upon said second layer a third layer comprising a nominally cubic metal oxide.
Dependencies are inferred from the claim text.