A new method for producing superconducting multi-layer transition-edge sensors has been proposed by researchers at NIST. The key innovation is the ability to pattern the first layer completely using a subtractive process before depositing and patterning subsequent layers with separate additive processes.
This approach offers several advantages:
1. Quality assurance: The first layer can be inspected before the second layer is deposited
2. New structure possibilities: Enables new bilayer transition-edge structures like meandering wires, parallel filaments, and meshes
3. Eliminates superconducting shorts: The normal metal layer can overhang the superconducting layer, eliminating the need for additional normal metal features
4. Extended to multilayers: The method is easily extended to structures with three or more layers
The main limitation is the need for highly uniform metal oxide removal processes, which the researchers have already demonstrated using vacuum energetic ion-based cleaning and atmospheric plasma cleaning methods.
This invention could significantly impact the fabrication of superconducting multi-layer transition-edge sensors, providing increased flexibility and enabling new sensor designs with improved performance.
Keywords: superconducting, transition-edge sensor, multilayer
