International Business Machines Corporation

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Corwin Paul Umbach

Robert B Laibowitz

Richard Joseph Gambino

Roger Hilsen Koch

Mordehai Heiblum

Gregory John Clark

Allan David Marwick

Alexander Palevski

Uri Sivan

A superconducting device operable at temperatures in excess of 30&#xb0; K. and a method for making the device are described. A representative device is an essentially coplanar SQUID device formed in a single layer of high Tsuperconducting material, the SQUID device being operable at temperatures in excess of 60&#xb0; K. High energy beams, for example ion beams, are used to convert selected portions of the high Tsuperconductor to nonsuperconductive properties so that the material now has both superconductive regions and nonsuperconductive regions. In this manner a superconducting loop having superconducting weak links can be formed to comprise the SQUID device.

Method for making a superconductor device

A lateral THETA device formed of a sandwich of first and second layers of semiconductor material forming a heterojunction therebetween and a two dimensional carrier gas in the second layer. First and second spaced electrodes are disposed on the surface of the first layer for inducing first and second potential barriers to the flow of charge carriers in the carrier gas. Ohmic contacts are deposited in the base region defined between the electrodes and in the emitter and collector regions defined on opposing sides of the electrodes. The width of the first electrode is formed narrow enough so that the first potential barrier beneath the electrode permits tunnelling of charge carriers into the base region. The width of the second electrode is wide enough so that the second potential barrier prevents tunnelling. Electrons tunnelling through the first barrier are hot and ballistically move through the base region to the collector.

Lateral theta device

The present invention relates to semiconductor devices which incorporate doped semiconductor elements or modulation doped devices wherein ballistic electrons in these elements or in a two-dimensional electron gas (2-DEG) are deflected by shaped potential barriers. A shaped potential barrier is formed by depositing a shaped electrode on the surface of the device and applying a potential to it. The electrode may take the shape of a biconcave lens which induces a potential barrier of that shape in the underlying device. Upon transiting the potential barrier induced by the shaped electrode, the phases of the exiting electrons are different across the width of the electrode and the beam of electrons is focused. By changing the applied potential, the focal point of the exiting electrons may be moved in a direction parallel to the axis of the lens-like electrode. Other electrode configurations such as a biconvex shape will cause incident electrons to diverge from their original paths. In another embodiment, a triangular electrode, depending on the potentials applied to it, reflects, transmits or deflects incident electron waves.

Electron wave deflection in modulation doped and other doped

A superconducting device operable at temperatures in excess of 30.degree. K. and a method for making the device are described. A representative device is an essentially coplanar SQUID device formed in a single layer of high T.sub.c superconducting material, the SQUID device being operable at temperatures in excess of 60.degree. K. High energy beams, for example ion beams, are used to convert selected portions of the high T.sub.c superconductor to nonsuperconductor properties so that the material now has both superconductive regions and nonsuperconductive regions. In this manner a superconducting loop having superconducting weak links can be formed to comprise the SQUID device.

Devices using high T.sub.c superconductors

A new solid state device based on mesoscopic phenomena is described. A structure of the mesoscopic device includes phase altering scattering sites at various energy levels disposed in proximity to a conductive channel. The carries in the channel, being isolated by a potential barrier, are not in substantial scattering interaction with the phase altering scattering sites in the absence of a sufficiently large voltage at the gate of the mesoscopic device. Increasing the potential at the gate, imposes a localized electric field along the channel, increases the energy levels of the carriers in the channel, and allows the carriers to interact with the phase altering scattering sites, thereby controllably varying the conductance of the channel.

Gated structure for controlling fluctuations in mesoscopic structures

This invention relates to an interconnection device which includes microminiaturized conductive interconnections between a pair of conductive layers and to a method for fabricating such devices. The conductive interconnections are made from normal metal, superconductors, low bandgap insulators, semimetals or semiconductors depending on the application, and form vias between the two layers of normal metallic, superconducting, low bandgap insulating, semimetallic or semiconducting materials, or any combination of these materials. The structure and method of the present invention revolve about contamination resist cone structures which are formed by irradiating a carbonaceous film such as silicone oil with an electron beam. After the contamination cones are formed on a substrate, using one fabrication approach, a conductive layer is deposited on a portion of a cone and over the structure. An insulating material is deposited conformally over the conductive layer and cone such that thickness of the insulating material over the conductive layer has a thickness less than the height of the contamination cone. Those portions of the insulation material, the conductive layer and the contamination cone which extend beyond the nominal surface of the insulating layer are removed, exposing a portion of the cone and a portion of the conductive layer which forms an interconnection. In a final step, another layer of conductive material is deposited on the insulation layer and on the exposed portion of the conductive interconnection and cone such that an electrically conductive interconnection is made between the just deposited conductive layer and the initially deposited conductive layer.

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Peekskill, NY, United States of America

Corwin Paul Umbach