A metal connection for an integrated circuit device is effectively "cast" in place at any level of an integrated circuit. The "mold" for the connection is formed by depositing and patterning a sacrificial material, such as aluminum oxide or other metal oxides, and covering the sacrificial material with a protective material such as silicon dioxide or other insulators. After forming bore holes to the deposit of sacrificial material through the protective layer, the sacrificial material is removed by isotropic etching to form a cavity beneath and at least partially overlaid by the protective layer. Alternatively, a defect may be produced below the protective layer and filled with metal either with or without enlargement by further removal of material. This cavity is then filled with metal by deposition of the metal by, for instance, evaporation, sputtering and chemical vapor deposition or combinations thereof. Connections formed by this technique can be produced at any level of the integrated circuit and do not interfere with surface wiring. A plurality of such connections may be simultaneously formed at the same or different levels of the integrated circuit and the method may be repeated to form multi-level wiring patterns.
An antifuse structure is formed between two metal contacts in which a thin oxide layer is formed on the first or bottom metal, a shallow via is provided oxide layer and a layer of amorphous silicon is deposited over the thin oxide and into the shallow via without leaving the usual furrows in the amorphous silicon and thereby eliminating the step coverage problems of cusps forming in the subsequently applied second or top metal.
An inter-level insulating structure is formed by a lower silicon oxide layer, an upper silicon oxide layer and an air layer filling a gap between the lower silicon oxide layer and the upper silicon oxide layer, and the air layer decreases the effective dielectric constant so that a parasitic capacitance across the inter-level insulating structure is drastically decreased.
A guide wire feeding device for operation by a single hand of a physician is disclosed. The device includes an elastic locking ring which allows the guide wire to be fixed in relative position with the feeding device if desired.
A method is described for forming an element of a microelectronic circuit. A sacrificial layer is formed on an upper surface of a support layer. The sacrificial layer is extremely thin and uniform. A height-defining layer is then formed on the sacrificial layer, whereafter the sacrificial layer is etched away so that a well-defined gap is left between an upper surface of the support layer and a lower surface of the height-defining layer. A monocrystalline semiconductor material is then selectively grown from a nucleation silicon site through the gap. The monocrystalline semiconductor material forms a monocrystalline layer having a thickness corresponding to the thickness of the original sacrificial layer.
A dual damascene method of fabricating an interconnection level of conductive lines and connecting vias separated by insulation for integrated circuits and substrate carriers for semiconductor devices using a sacrificial via fill. A first layer of insulating material is formed with via openings. The openings are filled with a sacrificial removable material. A second layer of insulating material is deposed on the first layer. In one embodiment, the etch selectivity to the etchant of the second layer is essentially the same as the sacrificial via fill and, preferably, is substantially higher than second layer. Using a conductive line pattern aligned with the via openings, conductive line openings are etched in the second insulating layer and, during etching, the sacrificial fill is removed from the via openings. In a second embodiment, the sacrificial material is not etchable by the etchant for forming the conductive line openings and, after formation of the conductive line openings, the sacrificial material is removed with an etchant to which the first insulating layer is resistive or less selective. A conductive material now is deposited in the conductive line and via openings.
