The present invention provides a method for manufacturing a wide-bandgap oxide epitaxial film. An epitaxial film with superior physical properties, such as high saturated drift velocity of electrons, small dielectric constant, high thermal stability, and excellent high-temperature resistance, is formed on a substrate. In addition, because the oxide epitaxial film is grown by metal-organic chemical vapor deposition (MOCVD), the yield is improved significantly and defects in the epitaxy is reduced.

The present invention provides a method for manufacturing a wide-bandgap oxide epitaxial film. An epitaxial film with superior physical properties, such as high saturated drift velocity of electrons, small dielectric constant, high thermal stability, and excellent high-temperature resistance, is formed on a substrate. In addition, because the oxide epitaxial film is grown by metal-organic chemical vapor deposition (MOCVD), the yield is improved significantly and defects in the epitaxy is reduced.

The present invention provides a thin film structural body comprising a sapphire substrate having a principal plane of a {11-26} plane and a first epitaxial thin film which is grown directly on the principal plane of the sapphire substrate and has a principal plane of a {100} plane. As one example, in a fabrication method of the thin film structural body, a first epitaxial thin film is grown on a principal plane of a {11-26} plane of the sapphire substrate. The grown first epitaxial thin film has a principal plane of a {100} plane.

The present invention provides a thin film structural body comprising a sapphire substrate having a principal plane of a {11-26} plane and a first epitaxial thin film which is grown directly on the principal plane of the sapphire substrate and has a principal plane of a {100} plane. As one example, in a fabrication method of the thin film structural body, a first epitaxial thin film is grown on a principal plane of a {11-26} plane of the sapphire substrate. The grown first epitaxial thin film has a principal plane of a {100} plane.

The present disclosure describes epitaxial oxide devices with impact ionization. In some embodiments, a semiconductor device comprises: a first semiconductor layer; a second semiconductor layer coupled to the first semiconductor layer; and a first and a second electrical contact coupled to the second and first semiconductor layers, respectively. The first semiconductor layer can comprise a first epitaxial oxide material with a first bandgap and an impact ionization region. The second semiconductor layer can comprise a second epitaxial oxide material with a second bandgap that is wider than the first bandgap.

The present disclosure provides techniques for epitaxial oxide materials, structures and devices. In some embodiments, a semiconductor structure includes an epitaxial oxide heterostructure, including: a substrate; a first epitaxial oxide layer comprising (Ni.sub.x1Mg.sub.y1Zn.sub.1-x1-y1)(Al.sub.q1Ga.sub.1-q1).sub.2O.sub.4 wherein 0?x1?1, 0?y1?1 and 0?q1?1; and a second epitaxial oxide layer comprising (Ni.sub.x2Mg.sub.y2Zn.sub.1-x2-y2)(Al.sub.q2Ga.sub.1-q2).sub.2O.sub.4 wherein 0?x2?1, 0?y2?1 and 0?q2?1. In some cases, at least one condition selected from x1?x2, y1?y2, and q1?q2 is satisfied.

The present disclosure describes methods and epitaxial oxide devices with impact ionization. A method can comprise: applying a bias across a semiconductor structure using a first electrical contact and a second electrical contact; injecting a hot electron, from the first electrical contact, through a second semiconductor layer, and into a conduction band of a first epitaxial oxide material; and forming an excess electron-hole pair in an impact ionization region of the first semiconductor layer via impact ionization. The semiconductor structure can comprise: the first electrical contact; the first semiconductor layer with the first epitaxial oxide material with a first bandgap coupled to the first electrical contact; a second semiconductor layer with a second epitaxial oxide material with a second bandgap coupled to the first semiconductor layer; and a second electrical contact coupled to the second semiconductor layer, wherein the second bandgap is wider than the first bandgap.

A method of in-situ transfer during fabrication of a component comprising a 2-dimensional crystalline thin film on a substrate is disclosed. In one embodiment, the method includes forming a layered structure comprising a polymer, a 2-dimensional crystalline thin film, a metal catalyst, and a substrate. The metal catalyst, being a growth medium for the two-dimensional crystalline thin film, is etched and removed by infiltrating liquid to enable the in-situ transfer of the two-dimensional crystalline thin film directly onto the underlying substrate.

A method of in-situ transfer during fabrication of a component comprising a 2-dimensional crystalline thin film on a substrate is disclosed. In one embodiment, the method includes forming a layered structure comprising a polymer, a 2-dimensional crystalline thin film, a metal catalyst, and a substrate. The metal catalyst, being a growth medium for the two-dimensional crystalline thin film, is etched and removed by infiltrating liquid to enable the in-situ transfer of the two-dimensional crystalline thin film directly onto the underlying substrate.

The present disclosure provides techniques for epitaxial oxide materials, structures and devices. In some embodiments, the techniques described herein relate to a transistor, including: a substrate including a first oxide material; an epitaxial oxide layer on the substrate including a second oxide material with a first bandgap; a gate layer on the epitaxial oxide layer, the gate layer including a third oxide material with a second bandgap, wherein the second bandgap is wider than the first bandgap; and electrical contacts. The second oxide material can include: one or two of Li, Ni, Al, Ga, Mg, and Zn; Ge; and O. The second oxide can also include (Ni.sub.xMg.sub.yZn.sub.1-x-y).sub.2GeO.sub.4 wherein 0x1 and 0y1. The electrical contacts can include: a source electrical contact coupled to the epitaxial oxide layer; a drain electrical contact coupled to the epitaxial oxide layer; and a first gate electrical contact coupled to the gate layer.