Perovskite oxides with a-axis orientation
AssigneeImec Vzw
InventorClement Merckling
Life of this patent
Estimating the term…
Abstract
A structure is provided and includes (i) a substrate having a surface, the surface comprising a ternary or quaternary oxide having a first lattice parameter, the first lattice parameter being a lattice parameter of the ternary or quaternary oxide as it is present at the surface; and (ii) a layer of a perovskite oxide on the ternary or quaternary oxide, the perovskite oxide having a second lattice parameter, the second lattice parameter being a native lattice parameter of the perovskite oxide, wherein the first lattice parameter is larger than the second lattice parameter. A method for forming a perovskite oxide with an a-axis orientation is also provided.
Claims15
A structure comprising:
- (i) a layer of a monocrystalline ternary or quaternary oxide on a Si(001) substrate or a Ge(001) substrate, the layer having a surface, the surface comprising a monocrystalline ternary or quaternary oxide having a crystalline unit cell having two perpendicular dimensions parallel to the surface and equal to a first lattice parameter, the first lattice parameter being a lattice parameter of the monocrystalline ternary or quaternary oxide as it is present at the surface;
- and
- (ii) a tensile strained layer of a monocrystalline perovskite oxide on the ternary or quaternary oxide, the monocrystalline perovskite oxide having in its tensile strained state a tetragonal crystalline unit cell characterized by lattice parameters a and c, wherein a refers to the dimension of the unit cell parallel to the top surface of the layer, wherein c refers to the dimension of the unit cell out of the plane of the top surface of the layer, wherein c is smaller than a, thereby giving an a-axis orientation to the tensile strained layer, and being selected from perovskite oxides having an in-plane second lattice parameter, being a native lattice parameter, and being smaller than the first lattice parameter.
A method for forming a tensile strained monocrystalline perovskite oxide layer having in its tensile strained state a tetragonal crystalline unit cell having lattice parameters a and c, wherein a refers to the dimension of the unit cell parallel to the top surface of the layer, wherein c refers to the dimension of the unit cell out of the plane of the top surface of the layer, wherein c is smaller than a thereby giving an a-axis orientation to the tensile strained perovskite oxide layer, the method comprising:
- (a) providing a layer of a monocrystalline ternary or quaternary oxide on a Si(001) substrate or a Ge(001) substrate, the layer having a surface, the surface comprising a monocrystalline ternary or quaternary oxide having a crystalline unit cell having two perpendicular dimensions parallel to the surface and equal to a first lattice parameter, the first lattice parameter being a lattice parameter of the ternary or quaternary oxide as it is present at the surface;
- and
- (b) depositing a layer of a perovskite oxide on the ternary or quaternary oxide, the perovskite oxide being selected from perovskite oxides having an in-plane second lattice parameter, being a native lattice parameter, and being smaller than the first lattice parameter.
Dependencies are inferred from the claim text.