Fabrication of superconducting through-silicon vias

Abstract

Increasing circuit complexity within quantum systems based on superconducting qubits necessitates high connectivity while retaining qubit coherence. Classical micro-electronic systems have addressed interconnect density challenges by using 3D integration with interposers containing through-silicon vias (TSVs), but extending these integration techniques to superconducting quantum systems is challenging. Here, we discuss our approach for realizing high-aspect-ratio superconducting TSVs\textemdash 10 $\mu$m wide by 20 $\mu$m long by 200 $\mu$m deep\textemdash with densities of 100 electrically isolated TSVs per square millimeter. We characterize the DC and microwave performance of superconducting TSVs at cryogenic temperatures and demonstrate superconducting critical currents greater than 20 mA. These high-aspect-ratio, high critical current superconducting TSVs will enable high-density vertical signal routing within superconducting quantum processors.

14 pages, 7 figures

References in corpus (3)

• Surface codes: Towards practical large-scale quantum computation
• Superconducting Through-Silicon Vias for Quantum Integrated Circuits
• Superconducting Caps for Quantum Integrated Circuits

Cited by in corpus (5)

• Qubit-compatible substrates with superconducting through-silicon vias
• Improved Parameter Targeting in 3D-Integrated Superconducting Circuits through a Polymer Spacer Process
• Material matters in superconducting qubits
• Low crosstalk modular flip-chip architecture for coupled superconducting qubits
• Low-loss liquid metal interconnects for superconducting quantum circuits