# US 11,442,297 B2 · Perovskite oxides with a-axis orientation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,442,297 B2 - Document ID: US11442297B2 - Status: Granted - Kind: B2 - Application number: 16/712,732 - Filed: 2019-12-12 - Published: 2020-06-25 - Granted: 2022-09-13 - Earliest claimed: 2018-12-20 - Assignees: Imec Vzw - Applicants: Imec Vzw - Inventors: Clement Merckling - Web page: https://patentgrep.com/patent/US11442297B2 ## CPC - G02F 1/03: based on ceramics or electro-optical crystals, e.g. exhibiting Pockels effect or Kerr effect (G02F1/061 takes precedence) - C23C 14/083: {of refractory metals or yttrium} - C23C 14/28: by wave energy or particle radiation (C23C14/32 - C23C14/48 take precedence) - C30B 23/025: {characterised by the substrate} - C30B 29/32: Titanates; Germanates; Molybdates; Tungstates - H10N 30/079: using intermediate layers, e.g. for growth control - H10N 30/708: {Intermediate layers, e.g. barrier, adhesion or growth control buffer layers} - H10N 30/8536: {Alkaline earth metal based oxides, e.g. barium titanates} - G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS - C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04) - C30B: SINGLE-CRYSTAL GROWTH (by using ultra-high pressure, e.g. for the formation of diamonds, B01J3/06); UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL (zone-refining of metals or alloys C22B); PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (casting of metals, casting of other substances by the same processes or devices B22D; working of plastics B29; modifying the physical structure of metals or alloys C21D, C22F); SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (for producing semiconductor devices or parts thereof H10); APPARATUS THEREFOR - H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR ## 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. ## Claims ### Claim 1 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. ### Claim 2 (depends on 1) The structure according to claim 1, wherein the first lattice parameter is from 0.05% to 3% larger than the second lattice parameter. ### Claim 3 (depends on 1) The structure according to claim 1, wherein the first lattice parameter is from 0.1% to 1.5% larger than the second lattice parameter. ### Claim 4 (depends on 1) The structure according to claim 1, wherein the ternary oxide has a general chemical formula ABO3 wherein A is selected from the group consisting of Ba, Sr, and Ca, and B is selected from the group consisting of Ti, Zr, and Hf. ### Claim 5 (depends on 1) The structure according to claim 1, wherein the quaternary oxide has a general chemical formula ABxB′1-xO3 wherein 0