Abstract:
Provided are superconducting tunnel junctions, such as Josephson tunnel junctions, and a method of fabricating thereof. A junction includes an insulator disposed between two superconductors. The junction may also include one or two interface layers, with each interface layer disposed between the insulator and one of the superconductors. The interface layer is configured to prevent oxygen from entering the adjacent superconductor during fabrication and operation of the junction. Furthermore, the interface layer may protect the insulator from the environment during handling and processing of the junction, thereby allowing vacuum breaks after the interface layer is formed as well as new integration schemes, such as depositing a dielectric layer and forming a trench in the dielectric layer for the second superconductor. In some embodiments, the junction may be annealed during its fabrication to move oxygen from the superconductors and/or from the insulator into the one or two interface layers.
Abstract:
A tunnel barrier layer in a superconducting device, such as a Josephson junction, is made from catalytically grown silicon dioxide at a low temperature (
Abstract:
An amorphous silicon (a-Si) dielectric for superconducting electronics is fabricated with reduced loss tangent by fluorine passivation throughout the bulk of the layer. Complete layers or thinner sub-layers of a-Si are formed by physical vapor deposition at low temperatures (
Abstract:
An amorphous silicon (a-Si) dielectric for superconducting electronics is fabricated with reduced loss tangent by fluorine passivation throughout the bulk of the layer. Complete layers or thinner sub-layers of a-Si are formed by physical vapor deposition at low temperatures (
Abstract:
Amorphous silicon (a-Si) is hydrogenated for use as a dielectric (e.g., an interlayer dielectric) for superconducting electronics. A hydrogenated a-Si layer is formed on a substrate by CVD or sputtering. The hydrogen may be integrated during or after the a-Si deposition. After the layer is formed, it is first annealed in an environment of high hydrogen chemical potential and subsequently annealed in an environment of low hydrogen chemical potential. Optionally, the a-Si (or an H-permeable overlayer, if added) may be capped with a hydrogen barrier before removing the substrate from the environment of low hydrogen chemical potential.
Abstract:
Provided are superconducting circuits, methods of operating these superconducting circuits, and methods of determining processing conditions for operating these superconducting circuits. A superconducting circuit includes a superconducting element, a conducting element, and a dielectric element disposed between the superconducting element and the conducting element. The conducting element may be another superconducting element, a resonating element, or a conducting casing. During operation of the superconducting element a direct current (DC) voltage is applied between the superconducting element and the conducting element. This application of the DC voltage reduces average microwave absorption of the dielectric element. In some embodiments, when the DC voltage is first applied, the microwave absorption may initially rise and then fall below the no-voltage absorption level. The DC voltage level may be determined by testing the superconducting circuit at different DC voltage levels and selecting the one with the lowest microwave absorption.
Abstract:
Amorphous silicon (a-Si) is hydrogenated for use as a dielectric (e.g., an interlayer dielectric) for superconducting electronics. A hydrogenated a-Si layer is formed on a substrate by CVD or sputtering. The hydrogen may be integrated during or after the a-Si deposition. After the layer is formed, it is first annealed in an environment of high hydrogen chemical potential and subsequently annealed in an environment of low hydrogen chemical potential. Optionally, the a-Si (or an H-permeable overlayer, if added) may be capped with a hydrogen barrier before removing the substrate from the environment of low hydrogen chemical potential.
Abstract:
Provided are methods of forming low resistivity contacts. Also provided are devices having such low resistive contacts. A method may include doping the surface of a structure, such as a gallium nitride layer. Specifically, a dopant containing layer is formed on the surface of the structure using, for example, atomic layer deposition (ALD). The dopant may magnesium. In some embodiments, the dopant containing layer also includes nitrogen. A capping layer may be then formed over the dopant containing layer to prevent dopant desorption. The stack including the structure with the dopant containing layer disposed on its surface is then annealed to transfer dopant from the dopant containing layer into the surface. After annealing, any remaining dopant containing layer is removed. When another component is later formed over the surface, a low resistivity contact is created between this other component and the doped structure.
Abstract:
Provided are superconducting circuits, methods of operating these superconducting circuits, and methods of determining processing conditions for operating these superconducting circuits. A superconducting circuit includes a superconducting element, a conducting element, and a dielectric element disposed between the superconducting element and the conducting element. The conducting element may be another superconducting element, a resonating element, or a conducting casing. During operation of the superconducting element a direct current (DC) voltage is applied between the superconducting element and the conducting element. This application of the DC voltage reduces average microwave absorption of the dielectric element. In some embodiments, when the DC voltage is first applied, the microwave absorption may initially rise and then fall below the no-voltage absorption level. The DC voltage level may be determined by testing the superconducting circuit at different DC voltage levels and selecting the one with the lowest microwave absorption.
Abstract:
A tunnel barrier layer in a superconducting device, such as a Josephson junction, is made from catalytically grown silicon dioxide at a low temperature (