Highly-Conformal Sputtered Through-Silicon Vias With Sharp Superconducting Transition

Journal of Microelectromechanical Systems, vol. 30, pp. 253–261

Abstract

This paper describes the microfabrication and electrical characterization of aluminum-coated superconducting through-silicon vias (TSVs) with sharp superconducting transition above 1 K. The sharp superconducting transition was achieved by means of fully conformal and void-free DC-sputtering of the TSVs with Al, and is here demonstrated in up to 500 μm-deep vias. Full conformality of Al sputtering was made possible by shaping the vias with a tailored hourglass profile, which allowed a metallic layer as thick as 430 nm to be deposited in the center of the vias. Single-via electric resistance as low as 160 mΩ at room temperature and superconductivity at 1.27 K were measured by a three-dimensional (3D) cross-bridge Kelvin resistor structure. This work establishes a CMOS-compatible fabrication process suitable for arrays of superconducting TSVs and 3D integration of superconducting silicon-based devices. [2020-0354].

Authors 7

1. J. A. Alfaro-Barrantes

   Instituto Tecnológico de Costa Rica · Delft University of Technology

   Affiliation as printed

   Electronic Components, Technology and Materials Group, Delft University of Technology, Delft, Netherlands

   Instituto Tecnológico de Costa Rica, Cartago, Costa Rica

2. Massimo Mastrangeli

   Delft University of Technology

   Affiliation as printed

   Electronic Components, Technology and Materials Group, Delft University of Technology, Delft, Netherlands

3. David J. Thoen

   Delft University of Technology

   Affiliation as printed

   Terahertz Sensing Group, Delft University of Technology, Delft, Netherlands

4. Sven Visser Aachen

   Space Research Organisation Netherlands

   Affiliation as printed

   SRON, Utrecht, Netherlands

5. Juan Bueno Aachen

   Space Research Organisation Netherlands · Delft University of Technology

   Affiliation as printed

   SRON, Utrecht, Netherlands

   Terahertz Sensing Group, Delft University of Technology, Delft, Netherlands

6. J. J. A. Baselmans Aachen

   Space Research Organisation Netherlands · Delft University of Technology

   Affiliation as printed

   SRON, Utrecht, Netherlands

   Terahertz Sensing Group, Delft University of Technology, Delft, Netherlands

7. Pasqualina Maria Sarro

   Delft University of Technology

   Affiliation as printed

   Electronic Components, Technology and Materials Group, Delft University of Technology, Delft, Netherlands