The FinMET
Abstract
Planar superconductor based transmon qubits based on the new merged element design will be fabricated using silicon fins as Josephson junctions to form fin-merged element transmons (FinMETs). This new technology will capitalize on the anisotropic etching of specific silicon atomic planes which will be used to define atomically flat, reproducible tunnel barriers with superconducting metal contacts on the side-wall surfaces. This process facilitates the preparation of single crystal barriers while circumventing the problems associated with the incompatibility of low-loss insulating barrier growth with lattice matched superconductors. In addition, it can be expected to address problems with standard superconducting transmon devices by; (1) reducing loss and thus increasing coherence; (2) reducing the formation of two-level system spectral features; (3) improving thickness control, especially when combined with commercial fin-fabrication, resulting in better frequency control; (4) dramatically reducing the footprint; and (5) allowing for more scalable fabrication. The Si fins will be formed using high-purity silicon substrates with a specific crystallographic orientation and will be metallized using aluminum deposition to make the superconducting electrodes. The formation of FinMET devices allows for controllable thickness, length, and height parameters of the tunnel junction using optical lithography and standard semiconductor processes. These devices provide the advantages of uniform fabrication based on existing infrastructure for finFETs while using cost effective bulk wafers and avoiding the use of lossy amorphous dielectrics.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 31, 2022
- Source ID
- W911NF2210052
Entities
People
- Chris J. Palmstrøm
Organizations
- Army Contracting Command
- National Security Agency
- University of California, Santa Barbara