Northrop Grumman Systems Corporation

Justin C Hackley

Jeffrey David Hartman

Aurelius L Graninger

Robert Miles Young

Joel D Strand

Zachary Keane

Micah John Atman Stoutimore

Aaron Ashley Hathaway

Patrick Loney

Edward R Engbrecht

Dustin Ray Johnson

Zachary Kyle Keane

Micah John Stoutimore

Jeffrey D Hartman

One embodiment of the invention includes a switch circuit including a first superconducting transmission line, a second superconducting transmission line and a phase-change material switch that is coupled between the first and second superconducting transmission lines. The phase-change material switch includes a switch portion that includes a phase-change material that is superconducting in a first state of the switch portion and blocking in a second state of the switch portion, such that the phase change material switch is configured to propagate an input signal from the first superconducting transmission line to the second superconducting transmission line in the first state, and to prohibit propagation of the input signal from the first superconducting transmission line to the second superconducting transmission line in the second state.

Superconducting phase-change material switch

A method of forming a multi-chip system is disclosed. The method includes forming one or more bumps on respective conductive contact pads of a first electronic device, forming one or more mini-bumps on respective conductive contact pads of a second electronic device, and aligning respective one or more mini-bumps with respective one or more bumps. The method further includes performing a bump bonding process that exerts compression force on one or both the first electronic device and the second electronic device to compress the one or more mini-bumps into the one or more bumps to form one or more bump bond structures that bond the second electronic device to the first electronic device.

Bump structures for low temperature chip bonding

Test structures and methods for superconducting bump bond electrical characterization are used to verify the superconductivity of bump bonds that electrically connect two superconducting integrated circuit chips fabricated using a flip-chip process, and can also ascertain the self-inductance of bump bond(s) between chips. The structures and methods leverage a behavioral property of superconducting DC SQUIDs to modulate a critical current upon injection of magnetic flux in the SQUID loop, which behavior is not present when the SQUID is not superconducting, by including bump bond(s) within the loop, which loop is split among chips. The sensitivity of the bump bond superconductivity verification is therefore effectively perfect, independent of any multi-milliohm noise floor that may exist in measurement equipment.

Superconducting bump bond electrical characterization

A superconducting structure includes a first superconducting device having a plurality of first superconducting contact pads disposed on a top side of a first superconducting device, a second superconducting device having a plurality of second superconducting contact pads disposed on a bottom side of a second superconducting device, and a plurality of superconducting bump structures with a given bump structure coupling respective superconducting contact pads of the plurality of first superconducting contact pads and the second plurality of superconducting pads to one another to bond the first superconducting device to the second superconducting device. Each superconducting bump structure includes a first under bump metallization (UBM) layer disposed on the top surface of a given superconducting contact pad, a second UBM layer disposed on the top surface of a given superconducting contact pads, and a superconducting metal layer coupling the first UBM layer to the second UBM layer.

Method for forming superconducting structures

A superconducting structure is provided that comprises a first superconducting device coupled to a second superconducting device employing a plurality of superconducting bump bond structures. Each of the plurality of superconducting bump bond structures comprise a first normal metal layer disposed on the top surface of a given one of a plurality of first contact pads, a second normal metal layer disposed on the top surface of a given one of a plurality of second contact pads, and a superconducting metal layer disposed between the first normal metal layer and the second normal metal layer. The metal thicknesses of each of the first normal metal layer, the second normal metal layer, and the specific material of the superconducting metal and normal metal are selected to inhibit the transfer of heat between the first superconducting device and the second superconducting device.

Multichip device with temperature isolating bump bonds

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Catonsville, MD, United States of America

Justin C Hackley