Fabrication of large and polymer-free complex oxide and complex nitride membranes assisted by isolated metal islands
OwnerChang-Beom Eom, Pratap Pal +1inventors
InventorsChang-Beom Eom, Pratap Pal, Yuchuan Yao
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Abstract
High-quality membranes of complex oxide and complex nitrides are provided. Also provided are method of making the membranes by releasing films of the complex oxides and nitrides from an epitaxial heterostructure using metal islands on the surface of the films as strain-absorbing supports. The methods facilitate the release of flat, large-area membranes characterized by the absence of, or a very low density of, cracks and/or wrinkles. The released membranes are free of the surface organic residues that are present on membranes released with the aid of a polymer support.
Claims20
A method of forming a membrane, the method comprising:
- providing an epitaxial heterostructure comprising:
- a substrate;
- a strained film comprising a single-crystal complex oxide or a single-crystal complex nitride in a strained state;
- and a sacrificial layer between the substrate and the strained film;
- forming metal islands on the top surface of the strained film;
- and
- immersing the epitaxial heterostructure in a liquid comprising an etchant to selectively etch away the sacrificial layer and release the strained film from the epitaxial heterostructure as a membrane of the single-crystal complex oxide or the single-crystal complex nitride, wherein the membrane is released without a top support, other than the metal islands, on its top surface.
A supported complex nitride membrane comprising a membrane bilayer consisting of a sublayer of an antiperovskite manganese nitride and an adjacent sublayer of SrTiO3 on a surface of a support platform, wherein the SrTiO3 sublayer is in contact with, but does not form an epitaxial interface with, the surface of the support platform.
A supported complex oxide membrane consisting of one or more layers of single-crystal perovskite oxide on a surface of a support platform, wherein one of the layers of single-crystal perovskite oxide is in contact with, but does not form an epitaxial interface with, the surface of the support platform, and further wherein the one or more layers of single-crystal perovskite oxide are free polymer residues and free of cracks and wrinkles over an area of at least 10 mm2.
Dependencies are inferred from the claim text.