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:
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:
In some embodiments, apparatus are provided that provide for flexible processing in high productivity combinatorial (HPC) system. The apparatus allow for interchangeable functionality that includes deposition, plasma treatment, ion beam treatment, in-situ annealing, and in-situ metrology. The apparatus are designed so that the functionality may be integrated within a single processing chamber for enhanced flexibility.
Abstract:
Systems and methods for rapid generation of ALD saturation curves using segmented spatial ALD are disclosed. Methods include introducing a substrate, having a plurality of substrate segment regions, into a processing chamber. The substrate may be disposed upon a pedestal within the chamber. Sequentially exposing the plurality of segment regions to a precursor within the chamber at a first processing temperature. Afterwards, purging the precursor from the chamber and then sequentially exposing each plurality of segment regions to a reactant within the chamber at the first processing temperature. Afterwards, purging the reactant from the chamber. Repeat sequentially exposing the plurality of segment regions to the precursor and the reactant for a plurality of cycles. Each segment region may be sequentially exposed to the precursor for a unique processing time. The pedestal may be rotated prior to exposing each next segment region to the precursor and the reactant.
Abstract:
Irradiation with ultraviolet (UV) light during atomic layer deposition (ALD) can be used to cleave unwanted bonds on the layer being formed (e.g., trapped precursor ligands or process-gas molecules). Alternatively, the UV irradiation can be used to excite the targeted bonds so they may be more easily cleaved by other means. The use of UV may enable the formation of low-defect-density films at lower deposition temperatures (e.g.,
Abstract:
A germanium-containing semiconductor surface is prepared for formation of a dielectric overlayer (e.g., a thin layer of high-k gate dielectric) by (1) removal of native oxide, for example by wet cleaning, (2) additional cleaning with hydrogen species, (3) in-situ formation of a controlled monolayer of GeO2, and (4) in-situ deposition of the dielectric overlayer to prevent uncontrolled regrowth of native oxide. The monolayer of GeO2 promotes uniform nucleation of the dielectric overlayer, but it too thin to appreciably impact the effective oxide thickness of the dielectric overlayer.
Abstract:
Provided are superconducting circuits and, more specifically, methods of forming such circuits. A method may involve forming a silicon-containing low loss dielectric (LLD) layer over a metal electrode such that metal carbides at the interface of the LLD layer and electrode. The LLD layer may be formed using chemical vapor deposition (CVD) at a temperature of less than about 500° C. At such a low temperature, metal silicides may not form even though silicon containing precursors may come in contact with metal of the electrode. Silicon containing precursors having silane molecules in which two silicon atoms bonded to each other (e.g., di-silane and tri-silane) may be used at these low temperatures. The LLD layer may include amorphous silicon, silicon oxide, or silicon nitride, and this layer may directly interface one or more metal electrodes. The thickness of LLD layer may be between about 1,000 Angstroms and 10,000 Angstroms.
Abstract:
Provided are superconducting circuits and method of forming thereof. A superconducting circuit may include a low loss dielectric (LLD) layer formed from one or both of polycrystalline silicon or polycrystalline germanium. The LLD layer may be formed at a low temperature (e.g., less than about 525° C.) using chemical vapor deposition (CVD). Addition of germanium may help to lower the deposition temperature and improve crystallinity of the resulting layer. The LLD layer is formed without adding silicides at the interface of the LLD layer and metal electrode. In some embodiments, an initial layer (e.g., a seed layer or a protective layer) may be formed on a metal electrode prior to forming the LLD layer. For example, the initial layer may include one of zinc sulfide, polycrystalline germanium, or polycrystalline silicon. The initial layer may be deposited at a low pressure (e.g., less than 10 Torr) to ensure higher levels of crystallinity.
Abstract:
Native oxide growth on germanium, silicon germanium, and InGaAs undesirably affects CET (capacitive equivalent thickness) and EOT (effective oxide thickness) of high-k and low-k metal-oxide layers formed on these semiconductors. Even if pre-existing native oxide is initially removed from the bare semiconductor surface, some metal oxide layers are oxygen-permeable in thicknesses below about 25 Å thick. Oxygen-containing species used in the metal-oxide deposition process may diffuse through these permeable layers, react with the underlying semiconductor, and re-grow the native oxide. To eliminate or mitigate this re-growth, the substrate is exposed to a gas or plasma reductant (e.g., containing hydrogen). The reductant diffuses through the permeable layers to react with the re-grown native oxide, detaching the oxygen and leaving the un-oxidized semiconductor. The reduction product(s) resulting from the reaction may then be removed from the substrate (e.g., driven off by heat).
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.