The techniques described herein relate to semiconductor structures, in some cases including epitaxial oxide heterostructures. An epitaxial oxide heterostructure can include a substrate, a first epitaxial oxide layer, and a second epitaxial oxide layer. The first epitaxial oxide layer can include a first epitaxial oxide material, where the first epitaxial oxide material includes: at least one of magnesium, nickel, and zinc; at least one of aluminum and gallium; and oxygen. The second epitaxial oxide layer can include a second epitaxial oxide material, where the second epitaxial oxide material includes: at least one of magnesium, nickel, and zinc; at least one of aluminum and gallium; and oxygen. The first epitaxial oxide material can have a first composition that is different from a second composition of the second epitaxial oxide material.

Method of making a quantum device with a quantum island structure, comprising the formation of a stack comprising a first semiconducting layer based on an undoped semiconducting material on which at least one second doped semiconducting layer is grown by epitaxy, the doping being made during epitaxial growth, a first region (212a) belonging to the first semiconducting layer and a second region (214a) belonging to the second semiconducting layer being suitable for forming a quantum island.

An electrical contact structure (an MIS contact) includes one or more conductors (M-Layer), a semiconductor (S-Layer), and an interfacial dielectric layer (I-Layer) of less than 4 nm thickness disposed between and in contact with both the M-Layer and the S-Layer. The I-Layer is an oxide of a metal or a semiconductor. The conductor of the M-Layer that is adjacent to and in direct contact with the I-Layer is a metal oxide that is electrically conductive, chemically stable and unreactive at its interface with the I-Layer at temperatures up to 450 C. The electrical contact structure has a specific contact resistivity of less than or equal to approximately 10.sup.5-10.sup.7 -cm.sup.2 when the doping in the semiconductor adjacent the MIS contact is greater than approximately 210.sup.19 cm.sup.3 and less than approximately 10.sup.8 -cm.sup.2 when the doping in the semiconductor adjacent the MIS contact is greater than approximately 10.sup.20 cm.sup.3.

A process for manufacturing a Schottky barrier field-effect transistor is provided. The process includes: providing a structure including a control gate and a semiconductive layer positioned under the gate and having protrusions that protrude laterally with respect to the gate; anisotropically etching at least one of the protrusions by using the control gate as a mask, so as to form a recess in this protrusion, this recess defining a lateral face of the semiconductive layer; depositing a layer of insulator on the lateral face of the semiconductive layer; and depositing a metal in the recess on the layer of insulator so as to form a contact of metal/insulator/semiconductor type between the deposit of metal and the lateral face of the semiconductive layer.

An electrical device in which an interface layer is disposed in between and in contact with a conductor and a semiconductor.

A tunnel field-effect transistor device includes a p-type GaN source layer, an n-type GaN drain layer, and an interlayer interfaced between the source-layer and the drain layer. In one example, the interlayer includes an Indium Nitride (InN) layer. In one example, the interlayer includes a graded Indium gallium nitride layer and an InN layer. In one example, the interlayer may include a graded Indium gallium nitride (In.sub.xGa.sub.1-xN) layer and an Indium gallium nitride (InGaN) layer. In one example, the tunnel field-effect transistor device includes an in-line configuration. In one example, the tunnel field-effect transistor device includes a side-wall configuration.

An electrical device in which an interface layer is disposed in between and in contact with a conductor and a semiconductor.

Forming a contact is disclosed. A trench through an interlayer dielectric layer is opened down to a substrate. The interlayer dielectric layer is formed on the substrate such that the substrate is the bottom surface of the trench. A cleaning process of the trench is performed. The bottom surface of the trench is recessed. A trench contact epitaxial layer is formed in the trench. An oxide layer is formed on top of the trench contact epitaxial layer in the trench. A metal oxide layer is formed on top of the oxide layer in the trench. A metal contact is formed on top of the metal oxide layer, where the oxide layer and the metal oxide layer together form a dipole layer.

Forming a contact is disclosed. A trench through an interlayer dielectric layer is opened down to a substrate. The interlayer dielectric layer is formed on the substrate such that the substrate is the bottom surface of the trench. A cleaning process of the trench is performed. The bottom surface of the trench is recessed. A trench contact epitaxial layer is formed in the trench. An oxide layer is formed on top of the trench contact epitaxial layer in the trench. A metal oxide layer is formed on top of the oxide layer in the trench. A metal contact is formed on top of the metal oxide layer, where the oxide layer and the metal oxide layer together form a dipole layer.