A device includes a first chip having a first circuit element, a first interconnect pad in electrical contact with the first circuit element, and a barrier layer on the first interconnect pad, a superconducting bump bond on the barrier layer, and a second chip joined to the first chip by the superconducting bump bond, the second chip having a first quantum circuit element, in which the superconducting bump bond provides an electrical connection between the first circuit element and the first quantum circuit element.

A device includes a first chip having a first circuit element, a first interconnect pad in electrical contact with the first circuit element, and a barrier layer on the first interconnect pad, a superconducting bump bond on the barrier layer, and a second chip joined to the first chip by the superconducting bump bond, the second chip having a first quantum circuit element, in which the superconducting bump bond provides an electrical connection between the first circuit element and the first quantum circuit element.

A method of manufacturing a bump structure includes forming a passivation layer over a substrate. A metal pad structure is formed over the substrate, wherein the passivation layer surrounds the metal pad structure. A polyimide layer including a polyimide is formed over the passivation layer and the metal pad structure. A metal bump is formed over the metal pad structure and the polyimide layer. The polyimide is a reaction product of a dianhydride and a diamine, wherein at least one of the dianhydride and the diamine comprises one selected from the group consisting of a cycloalkane, a fused ring, a bicycloalkane, a tricycloalkane, a bicycloalkene, a tricycloalkene, a spiroalkane, and a heterocyclic ring.

A device (100) includes a first chip (104) having a first circuit element (112), a first interconnect pad (116) in electrical contact (118) with the first circuit element, and a barrier layer (120) on the first interconnect pad, a superconducting bump bond (106) on the barrier layer, and a second chip (102) joined to the first chip by the superconducting bump bond, the second chip having a quantum circuit element (108), in which the superconducting bump bond provides an electrical connection between the first circuit element and the quantum circuit element.

A device (100) includes a first chip (104) having a first circuit element (112), a first interconnect pad (116) in electrical contact (118) with the first circuit element, and a barrier layer (120) on the first interconnect pad, a superconducting bump bond (106) on the barrier layer, and a second chip (102) joined to the first chip by the superconducting bump bond, the second chip having a quantum circuit element (108), in which the superconducting bump bond provides an electrical connection between the first circuit element and the quantum circuit element.

A device includes: a first chip including a qubit; and a second chip bonded to the first chip, the second chip including a substrate including first and second opposing surfaces, the first surface facing the first chip, wherein the second chip includes a single layer of superconductor material on the first surface of the substrate, the single layer of superconductor material including a first circuit element. The second chip further includes a second layer on the second surface of the substrate, the second layer including a second circuit element. The second chip further includes a through connector that extends from the first surface of the substrate to the second surface of the substrate and electrically connects a portion of the single layer of superconducting material to the second circuit element.

A device includes: a first chip including a qubit; and a second chip bonded to the first chip, the second chip including a substrate including first and second opposing surfaces, the first surface facing the first chip, wherein the second chip includes a single layer of superconductor material on the first surface of the substrate, the single layer of superconductor material including a first circuit element. The second chip further includes a second layer on the second surface of the substrate, the second layer including a second circuit element. The second chip further includes a through connector that extends from the first surface of the substrate to the second surface of the substrate and electrically connects a portion of the single layer of superconducting material to the second circuit element.

A core material including a core and a solder plating layer of a (SnBi)-based solder alloy made of Sn and Bi on a surface of the core. Bi in the solder plating layer is distributed in the solder plating layer at a concentration ratio in a predetermined range of, for example, 91.7% to 106.7%. Bi in the solder plating layer is homogeneous, and thus, a Bi concentration ratio is in a predetermined range over the entire solder plating layer including an inner circumference side and an outer circumference side in the solder plating layer.

A cryogenic electronic package includes a first superconducting multi-chip module (SMCM), a superconducting interposer, a second SMCM and a superconducting semiconductor structure. The interposer is disposed over and coupled to the first SMCM, the second SMCM is disposed over and coupled to the interposer, and the superconducting semiconductor structure is disposed over and coupled to the second SMCM. The second SMCM and the superconducting semiconductor structure are electrically coupled to the first SMCM through the interposer. A method of fabricating a cryogenic electronic package is also provided.

A cryogenic electronic package includes a first superconducting multi-chip module (SMCM), a superconducting interposer, a second SMCM and a superconducting semiconductor structure. The interposer is disposed over and coupled to the first SMCM, the second SMCM is disposed over and coupled to the interposer, and the superconducting semiconductor structure is disposed over and coupled to the second SMCM. The second SMCM and the superconducting semiconductor structure are electrically coupled to the first SMCM through the interposer. A method of fabricating a cryogenic electronic package is also provided.