A quantum computing system that includes a quantum circuit device having at least one operating frequency; a first substrate having a first surface on which the quantum circuit device is disposed; a second substrate having a first surface that defines a recess of the second substrate, the first and second substrates being arranged such that the recess of the second substrate forms an enclosure that houses the quantum circuit device; and an electrically conducting layer that covers at least a portion of the recess of the second substrate.

This application discloses a coating method for making a chip. The method includes: fixing a substrate on a base. The substrate includes a hole. The method includes controlling an included angle between a plane on which the substrate is located and a deposition direction of a coating material to be greater than 0 degrees and less than 90 degrees. The method includes controlling the substrate to rotate with respect to an axis perpendicular to the plane on which the substrate is located. The method includes during the rotation of the substrate, controlling the coating material to enter the hole along the deposition direction such that the coating material is deposited on a sidewall of the hole.

An integrated circuit comprises a first circuit element operably connected to a second circuit element by a nanowire interconnect; wherein the nanowire interconnect comprises molybdenum phosphide (MoP), tungsten phosphide (WP.sub.2), or niobium phosphide (NbP). A nanowire interconnect can be made by providing a template nanowire; providing a phosphine source; producing phosphine from the phosphine source; and contacting the template nanowire with the phosphine. The nanowire interconnect demonstrates low resistance.

Certain aspects of the present disclosure are generally directed to techniques and apparatus for adjusting capacitance in one or more metal-insulator-metal (MIM) capacitors in an effort to reduce capacitance variation between semiconductor devices and improve yield during fabrication. One example method for fabricating a semiconductor device generally includes measuring a capacitance value of a MIM capacitor of the semiconductor device, determining the measured capacitance value of the MIM capacitor is above a target capacitance value for the MIM capacitor, and selectively rupturing a set of connections in the MIM capacitor based on the measured capacitance value. Selectively rupturing the set of connections in the MIM capacitor may reduce the capacitance value of the MIM capacitor to a value approximately that of the target capacitance value.

The invention concerns an inteconnect device for interconnection between lines of superconducting material at least one via in contact with those lines, comprising:

a) a first substrate, which carries at least one first line of a first superconducting material;
b) at least one first via of a second superconducting material, different from the first superconducting material, said at least one first line being disposed between said first substrate and said first via;
c) at least one second line above said first via and in contact with the latter.

A qubit coupling device includes: a dielectric substrate including a trench; a first superconductor layer on a surface of the dielectric substrate where an edge of the first superconductor layer extends along a first direction and at least a portion of the superconductor layer is in contact with the surface of the dielectric substrate, and where the superconductor layer is formed from a superconductor material exhibiting superconductor properties at or below a corresponding critical temperature; a length of the trench within the dielectric substrate is adjacent to and extends along an edge of the first superconductor layer in the first direction, and where the electric permittivity of the trench is less than the electric permittivity of the dielectric substrate.

Various techniques and apparatus permit fabrication of superconductive circuits. A niobium/aluminum oxide/niobium trilayer may be formed and individual Josephson Junctions (JJs) formed. A protective cap may protect a JJ during fabrication. A hybrid dielectric may be formed. A superconductive integrated circuit may be formed using a subtractive patterning and/or additive patterning. A superconducting metal layer may be deposited by electroplating and/or polished by chemical-mechanical planarization. The thickness of an inner layer dielectric may be controlled by a deposition process. A substrate may include a base of silicon and top layer including aluminum oxide. Depositing of superconducting metal layer may be stopped or paused to allow cooling before completion. Multiple layers may be aligned by patterning an alignment marker in a superconducting metal layer.

Certain aspects of the present disclosure are generally directed to techniques and apparatus for adjusting capacitance in one or more metal-insulator-metal (MIM) capacitors in an effort to reduce capacitance variation between semiconductor devices and improve yield during fabrication. One example method for fabricating a semiconductor device generally includes measuring a capacitance value of a MIM capacitor of the semiconductor device, determining the measured capacitance value of the MIM capacitor is above a target capacitance value for the MIM capacitor, and selectively rupturing a set of connections in the MIM capacitor based on the measured capacitance value. Selectively rupturing the set of connections in the MIM capacitor may reduce the capacitance value of the MIM capacitor to a value approximately that of the target capacitance value.

A qubit coupling device includes: a dielectric substrate including a trench; a first superconductor layer on a surface of the dielectric substrate where an edge of the first superconductor layer extends along a first direction and at least a portion of the superconductor layer is in contact with the surface of the dielectric substrate, and where the superconductor layer is formed from a superconductor material exhibiting superconductor properties at or below a corresponding critical temperature; a length of the trench within the dielectric substrate is adjacent to and extends along an edge of the first superconductor layer in the first direction, and where the electric permittivity of the trench is less than the electric permittivity of the dielectric substrate.

Various techniques and apparatus permit fabrication of superconductive circuits. A superconducting integrated circuit comprising a superconducting stud via, a kinetic inductor, and a capacitor may be formed. Forming a superconducting stud via in a superconducting integrated circuit may include masking with a hard mask and masking with a soft mask. Forming a superconducting stud via in a superconducting integrated circuit may include depositing a dielectric etch stop layer. Interlayer misalignment in the fabrication of a superconducting integrated circuit may be measured by an electrical vernier. Interlayer misalignment in the fabrication of a superconducting integrated circuit may be measured by a chain of electrical verniers and a Wheatstone bridge. A superconducting integrated circuit with three or more metal layers may include an enclosed, matched, on-chip transmission line. A metal wiring layer in a superconducting integrated circuit may be encapsulated.