A device includes a first semiconductor layer; a portion of a second semiconductor layer disposed on the first semiconductor layer; and a third semiconductor layer including a first region disposed on the portion of the second semiconductor layer and a second region disposed on the first semiconductor layer. A thickness of the first region is less than a predefined thickness. The device also includes an etch stop layer disposed on the third semiconductor layer; a plurality of distinct portions of a fourth semiconductor layer disposed on the etch stop layer and exposing one or more distinct portions of the etch stop layer over the portion of the second semiconductor layer; and a plurality of distinct portions of a superconducting layer disposed on the plurality of distinct portions of the fourth semiconductor layer and the exposed one or more distinct portions of the etch stop layer.

Techniques and methods to form smooth metal layers deposited onto selected surfaces of Josephson junction devices are provided. For example, one or more embodiments described herein can comprise depositing a layer of a first material comprising metal atom species on a selected surface of a device layer; depositing a layer of a second material on a surface of the layer of first material; and performing plasma etching on the layer of second material and the layer of first material to form an etched surface of the layer of first material that is smoother than the surface of the layer of first material, as deposited.

Embodiments are provided for fabrication of superconducting devices using area-selective deposition of a metal nitride. In some embodiments, a method can include providing a thermally treated carbon layer, and selectively depositing a metal nitride using the thermally treated carbon layer for formation of a superconducting device.

A technique relates to a structure. A first surface includes an inductive element of a resonator. A second surface includes a first portion of a capacitive element of the resonator and at least one qubit. A second portion of the capacitive element of the resonator is on the first surface.

A cryogenic electronic package includes a circuitized substrate, an interposer, a superconducting multichip module (SMCM) and at least one superconducting semiconductor structure. The at least one superconducting semiconductor structure is disposed over and coupled to the SMCM, and the interposer is disposed between the SMCM and the substrate. The SMCM and the at least one superconducting semiconductor structure are electrically coupled to the substrate through the interposer. A cryogenic electronic assembly including a plurality of cryogenic electronic packages is also provided.

A substrate processing method is described for forming a titanium nitride material that may be used for superconducting metallization or work function adjustment applications. The substrate processing method includes depositing by vapor phase deposition at least one monolayer of a first titanium nitride film on a substrate, and treating the first titanium nitride film with plasma excited hydrogen-containing gas, where the first titanium nitride film is polycrystalline and the treating increases the (200) crystallographic texture of the first titanium nitride film. The method further includes depositing by vapor phase deposition at least one monolayer of a second titanium nitride film on the treated at least one monolayer of the first titanium nitride film, and treating the at least one monolayer of the second titanium nitride film with plasma excited hydrogen-containing gas.

Embodiments are directed to a superconducting microwave circuit. The circuit includes a substrate and two electrodes. The latter form an electrode pair dimensioned so as to support an electromagnetic field, which allows the circuit to be operated in the microwave domain. The substrate exhibits a raised portion, which includes a top surface and two lateral surfaces. The top surface connects the two lateral surfaces, which show respective undercuts (on the lateral sides of the raised portions). Each of the electrodes includes a structure that includes a potentially superconducting material. Two protruding structures are accordingly formed, which are shaped complementarily to the respective undercuts. This way, the shaped structure of each of the electrodes protrudes toward the other one of the electrodes of the pair.

Embodiments are directed to a superconducting microwave circuit. The circuit includes a substrate and two electrodes. The latter form an electrode pair dimensioned so as to support an electromagnetic field, which allows the circuit to be operated in the microwave domain. The substrate exhibits a raised portion, which includes a top surface and two lateral surfaces. The top surface connects the two lateral surfaces, which show respective undercuts (on the lateral sides of the raised portions). Each of the electrodes includes a structure that includes a potentially superconducting material. Two protruding structures are accordingly formed, which are shaped complementarily to the respective undercuts. This way, the shaped structure of each of the electrodes protrudes toward the other one of the electrodes of the pair.

A method for preparing multi-superconducting material layers includes: depositing a first superconducting material layer on a substrate, the first superconducting material layer being formed by covering a first superconducting material in a first target region range with a first hard mask in the first target region range; depositing a second superconducting material on the substrate deposited with the first superconducting material layer; covering the second superconducting material with a second hard mask; and performing etching treatment on the second hard mask and the second superconducting material to obtain a second superconducting material layer formed by covering the second superconducting material in a second target region range with the second hard mask in the second target region range.

A device includes: a substrate; a first superconductor layer on the substrate, the first superconductor layer having a first kinetic inductance; and a second superconductor layer on the first superconductor layer, the second superconductor layer having a second kinetic inductance that is lower than the first kinetic inductance, in which the second superconductor layer covers the first superconductor layer such that the second superconductor layer and the first superconductor layer have a same footprint, with the exception of at least a first region where the second superconductor layer is omitted so that the first superconductor layer and the second superconductor layer form a circuit element having a predetermined circuit parameter.