Search
Patexia Research
Patent No. US 11226507
Issue Date Jan 18, 2022
Claim this patent
PDF Unavailable

Patent 11226507 - Method and system for formation of stabilized tetragonal barium titanate > Claims

  • 1. A method comprising: depositing a seed layer on a substrate;epitaxially depositing a first electro-optic material layer on the seed layer;annealing the substrate, the seed layer, and the first electro-optic material layer in an oxygen environment, thereby forming an oxide buffer layer between the substrate and the seed layer;cooling the substrate after the annealing, thereby causing the first electro-optic material layer to be under tensile stress;depositing a first interlayer on the first electro-optic material layer, wherein the first interlayer includes a material that maintains a first lattice structure at room temperature and a cryogenic temperature;depositing a second electro-optic material layer on the first interlayer; andannealing the second electro-optic material layer and the first interlayer.
    • 2. The method of claim 1, wherein the first electro-optic material layer and the second electro-optic material layer include an electro-optic material characterized by a second lattice structure at the cryogenic temperature different from a third lattice structure at the room temperature.
      • 3. The method of claim 2, wherein the third lattice structure is a same crystal structure as the first lattice structure.
    • 4. The method of claim 1, wherein annealing the substrate, the seed layer, and the first electro-optic material layer includes annealing at a temperature above a softening temperature of the oxide buffer layer.
    • 5. The method of claim 1, further comprising: depositing a second interlayer on the second electro-optic material layer, wherein the second interlayer includes the material that maintains the first lattice structure at the room temperature and the cryogenic temperature;depositing a third electro-optic material layer on the second interlayer; andannealing the third electro-optic material layer and the second interlayer.
      • 6. The method of claim 5, further comprising: patterning the third electro-optic material layer to form a waveguide core; anddepositing a dielectric cladding layer on the waveguide core.
        • 7. The method of claim 6, wherein patterning the third electro-optic material layer includes etching the third electro-optic material layer using the second interlayer as an etch stop layer.
      • 8. The method of claim 5, further comprising forming a waveguide on the third electro-optic material layer.
        • 9. The method of claim 8, wherein forming the waveguide on the third electro-optic material layer includes: forming a waveguide core on the third electro-optic material layer; anddepositing a dielectric cladding layer on the waveguide core.
        • 10. The method of claim 8, wherein forming the waveguide on the third electro-optic material layer includes bonding a wafer including the waveguide to the third electro-optic material layer.
        • 11. The method of claim 8, further comprising: etching trenches in the first, second, and third electro-optic material layers and the first and second interlayers; andfilling the trenches with a conductive material.
    • 12. The method of claim 1, wherein a ratio between a thickness of the first electro-optic material layer and a thickness of the first interlayer is equal to or less than 20:1.
  • 13. A method comprising: providing a substrate;forming a first electro-optic material layer on the substrate;forming a buffer layer between the substrate and the first electro-optic material layer;cooling the substrate after the forming the buffer layer;forming a first interlayer on the first electro-optic material layer, wherein the first interlayer includes a material that maintains a first lattice structure at room temperature and a cryogenic temperature;forming a second electro-optic material layer on the first interlayer; andannealing the second electro-optic material layer and the first interlayer,wherein the cooling the substrate after the annealing causes the first electro-optic material layer to be under tensile stress.
    • 14. The method of claim 13 wherein the substrate includes a seed layer and wherein the first electro-optic material layer is deposited on the seed layer.
      • 15. The method of claim 14 wherein the first electro-optic material layer is epitaxially deposited on the seed layer.
      • 16. The method of claim 14 wherein the buffer layer is formed by annealing the substrate, the seed layer and the first electro-optic material layer in an oxygen environment.
        • 17. The method of claim 16 wherein the buffer layer comprises an oxide buffer layer that is formed between the substrate and the seed layer.
    • 18. The method of claim 13 wherein the first electro-optic material layer, the first interlayer, and the second electro-optic material layer are formed using a deposition process.
    • 19. The method of claim 13 wherein the buffer layer relieves stress between the first electro-optic material layer and the substrate.
Menu