Abstract: In a “window-junction” formation process for Josephson junction fabrication, a spacer dielectric is formed over the first superconducting electrode layer, then an opening (the “window” is formed to expose the part of the electrode layer to be used for the junction. In an atomic layer deposition (ALD) chamber (or multi-chamber sealed system) equipped with direct or remote plasma capability, the exposed part of the electrode is sputter-etched with Ar, H2, or a combination to remove native oxides, etch residues, and other contaminants. Optionally, an O2 or O3 pre-clean may precede the sputter etch. When the electrode is clean, the tunnel barrier layer is deposited by ALD in-situ without further oxidant exposure.

Abstract: Metal oxide tunnel barrier layers for superconducting tunnel junctions are formed by atomic layer deposition. Both precursors include a metal (which may be the same metal or may be different). The first precursor is a metal alkoxide with oxygen bonded to the metal, and the second precursor is an oxygen-free metal precursor with an alkyl-reactive ligand such as a halogen or methyl group. The alkyl-reactive ligand reacts with the alkyl group of the alkoxide, forming a detached by-product and leaving a metal oxide monolayer. The temperature is selected to promote the reaction without causing the metal alkoxide to self-decompose. The oxygen in the alkoxide precursor is bonded to a metal before entering the chamber and remains bonded throughout the reaction that forms the monolayer. Therefore, the oxygen used in this process has no opportunity to oxidize the underlying superconducting electrode.

Abstract: Defects in hydrogenated amorphous silicon are reduced by low-energy ion treatments and optional annealing. The treatments leave strongly-bonded hydrogen and other passivants in place, but increase the mobility of loosely-bonded and interstitially trapped hydrogen that would otherwise form unwanted two-level systems (TLS). The mobilized hydrogen atoms may be attracted to unused passivation sites or recombined into H2 gas and diffuse out of the deposited layer. The treatments also increase the density of the material. The optional anneal may partially crystallize the layer, further densify the layer, or both. The reduced number of defects and the increased crystallinity reduce the loss tangent of amorphous silicon dielectrics for superconducting microwave devices.

Abstract: A interconnect structure for superconducting devices uses a material with a high melting point for the superconductive wiring; examples include refractory metals such as niobium. Because the wiring is tolerant of high temperatures, the interlayer dielectric (e.g., amorphous silicon with or without small amounts of passivants such as hydrogen or fluorine) may be subjected to rapid thermal annealing to reduce defects by driving off excess hydrogen, and optionally partially crystallizing the material.

Abstract: Defects in hydrogenated amorphous silicon are reduced by low-energy ion treatments and optional annealing. The treatments leave strongly-bonded hydrogen and other passivants in place, but increase the mobility of loosely-bonded and interstitially trapped hydrogen that would otherwise form unwanted two-level systems (TLS). The mobilized hydrogen atoms may be attracted to unused passivation sites or recombined into H2 gas and diffuse out of the deposited layer. The treatments also increase the density of the material. The optional anneal may partially crystallize the layer, further densify the layer, or both. The reduced number of defects and the increased crystallinity reduce the loss tangent of amorphous silicon dielectrics for superconducting microwave devices.

Abstract: Metal oxide tunnel barrier layers for superconducting tunnel junctions are formed by atomic layer deposition. Both precursors include a metal (which may be the same metal or may be different). The first precursor is a metal alkoxide with oxygen bonded to the metal, and the second precursor is an oxygen-free metal precursor with an alkyl-reactive ligand such as a halogen or methyl group. The alkyl-reactive ligand reacts with the alkyl group of the alkoxide, forming a detached by-product and leaving a metal oxide monolayer. The temperature is selected to promote the reaction without causing the metal alkoxide to self-decompose. The oxygen in the alkoxide precursor is bonded to a metal before entering the chamber and remains bonded throughout the reaction that forms the monolayer. Therefore, the oxygen used in this process has no opportunity to oxidize the underlying superconducting electrode.

Abstract: In a “window-junction” formation process for Josephson junction fabrication, a spacer dielectric is formed over the first superconducting electrode layer, then an opening (the “window” is formed to expose the part of the electrode layer to be used for the junction. In an atomic layer deposition (ALD) chamber (or multi-chamber sealed system) equipped with direct or remote plasma capability, the exposed part of the electrode is sputter-etched with Ar, H2, or a combination to remove native oxides, etch residues, and other contaminants. Optionally, an O2 or O3 pre-clean may precede the sputter etch. When the electrode is clean, the tunnel barrier layer is deposited by ALD in-situ without further oxidant exposure.

Abstract: A computing system and bus bridge in which the bus bridge includes a buffer pool wherein the storage buffers contained in the buffer pool may be allocated as post buffers or fetch buffers in response to appropriate requests from the bus bridge. In the preferred embodiment, the bus bridge includes a buffer pool control unit adapted to temporarily allocate any of the plurality of storage buffers as either a post buffer or a fetch buffer depending upon the system requirements. Broadly speaking, the present invention contemplates a computing system including a first component connected to a first bus, a second component connected to a second bus, and a bus bridge connected to a first and second busses. The bus bridge includes a buffer pool comprised of a plurality of storage buffers and a buffer pool control unit that is capable of temporarily allocating at least one of the storage buffers as either a post buffer or a fetch buffer in response to system requirement.

Abstract: A cache memory system comprising a first bus for connecting to a bus master and a second bus for connecting to a system memory. The system memory comprises a plurality of cacheable memory locations. A bus bridge provides an interface between the first bus and the second bus. A cache memory controller for caching data stored in the cacheable memory locations is connected to the system memory. The cache memory controller includes a snoop control circuit directly coupled to the first bus for snooping bus transactions upon the first bus and further coupled to the second bus for snooping bus transactions on said second bus.