Vertical Silicon-on-Metal SQUID Layout for Small-Footprint Flux Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Superconducting quantum interference devices (SQUIDs) have large footprints due to the size of the loop area and can only detect fields orthogonal to the loop, limiting their application in certain circuits.
Innovation Solution
A vertical silicon-on-metal SQUID structure is developed, comprising a silicon-on-metal substrate with a first superconducting layer between crystalline silicon layers, and via structures forming Josephson junctions, allowing for an electrical loop that reduces footprint and enables detection of fields parallel to the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional planar Josephson junctions are used, then fabrication is relatively simple, but the critical current density is limited and device footprint is large
Solution Approach 1:
The patent transitions from planar two-dimensional Josephson junctions to three-dimensional vertical junctions grown epitaxially through multiple layers. This dimensional change enables higher critical current densities while maintaining fabrication compatibility with existing semiconductor processes, resolving the contradiction between fabrication simplicity and device performance.
2Manufacturing precision
If conventional planar Josephson junctions are used, then fabrication is relatively simple, but device footprint is large
Solution Approach 1:
By stacking multiple superconducting and insulating layers vertically to form a three-dimensional junction structure, the patent achieves high performance within a small planar footprint. The vertical configuration allows multiple junctions to be stacked, dramatically reducing the area required per junction while maintaining fabrication simplicity through epitaxial growth.
3Reliability
If vertical Josephson junctions are implemented, then critical current density and footprint are improved, but fabrication complexity increases
Solution Approach 1:
The patent combines multiple superconducting layers, insulating barriers, and magnetic tunnel junctions into a single vertically-integrated epitaxial structure. This merging of multiple functional components into one monolithic device reduces the number of separate fabrication steps and simplifies the overall manufacturing process while achieving high critical current density.
Solution Approach 2:
The vertical Josephson junction structure serves multiple functions simultaneously: it provides high critical current density, enables small footprint, incorporates magnetic tunneling for fluxon detection, and maintains compatibility with standard semiconductor fabrication. This multi-functionality resolves the complexity issue by making the single structure accomplish what would otherwise require multiple separate components.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The vertical silicon-on-metal SQUID structure reduces the footprint of SQUIDs and allows for the detection of magnetic fields parallel to the substrate, enhancing their applicability in quantum computing and other circuits.
Implementation Method 1
a first via between, and in contact with, a first section of the first superconducting layer and a first portion of a second superconducting layer, the first via comprises a first Josephson junction
Implementation Method 2
a silicon-on-metal substrate comprising a first superconducting layer between a first crystalline silicon layer and a second crystalline silicon layer
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Techniques related to vertical silicon-on-metal superconducting quantum interference devices and method of fabricating the same are provided. Also provided are associated flux control and biasing circuitry. A superconductor structure (500) comprises a silicon- on-metal substrate that comprises a first superconducting layer (302), comprising a first superconducting material, between a first crystalline silicon layer (106) and a second crystalline silicon layer (110). The superconducting structure also comprises a first via (502) comprising a first Josephson junction (506) and a second via comprising (504) a second Josephson junction (516). The first via (502) and the second via (504) are formed between the first superconducting layer (302) and a second superconducting layer (522), comprising a second superconducting material. An electrical loop around a defined area of the second crystalline silicon layer (110) comprises the first via (502) comprising the first Josephson junction (506), the second via (504) comprising the second Josephson junction (516), the first superconducting layer (302), and the second superconducting layer (522).