Angled Nanowire Deposition for Cleaner Semiconductor-Superconductor Interfaces
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The fabrication of semiconductor-superconductor platforms for topological quantum computing faces challenges due to 'soft gap' states in semiconductor-superconductor nanowires, which cause decoherence, primarily attributed to disorder at the SE/SU interface.
Innovation Solution
A method involving directional deposition using angled beams and shadow walls to selectively deposit materials on semiconductor nanowires, preventing unwanted material coverage and reducing impurities, thereby improving the quality of the SE/SU interface and minimizing decoherence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If material is deposited using a normal incident beam, then complete coverage of the nanowire is achieved, but unwanted material coverage occurs in regions where deposition should be prevented
Solution Approach 1:
The patent introduces a new dimension by tilting the deposition beam at an angle of incidence between 10-80 degrees relative to the substrate normal. This angular dimension allows the beam to selectively illuminate only certain regions of the nanowire, creating shadow regions where material should not deposit. This resolves the contradiction by adding spatial selectivity through angular control, preventing unwanted coverage while maintaining precise material deposition where needed.
2Manufacturing precision
If shadow walls are used to prevent unwanted deposition, then material purity is improved, but device complexity increases
Solution Approach 1:
The patent extracts and removes the shadow walls from the final device structure. The shadow walls are used only temporarily during the deposition process to define shadow regions, then they are removed completely. This approach achieves precise patterning during fabrication without leaving residual structures that would increase device complexity, thus resolving the contradiction between patterning precision and device complexity.
3Ease of manufacture
If conventional deposition methods are used, then fabrication process is simple, but soft gap decoherence occurs due to interface disorder
Solution Approach 1:
The patent changes the critical parameter of beam angle of incidence from the conventional 0 degrees (normal incidence) to an angled range of 10-80 degrees. This parameter change enables selective area deposition that prevents material coverage in shadow regions, thereby reducing interface disorder and soft gap states. The modified deposition geometry improves quantum state stability by creating cleaner semiconductor-superconductor interfaces without significantly complicating the fabrication process.
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
This approach enables the creation of stable semiconductor-superconductor nanowires with reduced soft gap decoherence, facilitating the development of fault-tolerant quantum computing platforms by ensuring high material purity and precise patterning without chemical contact, which degrades the surface properties.
Implementation Method 1
A beam is used to form a layer of material, at least part of which is in direct contact with a semiconductor structure on the substrate
Data Source
AI summary
Various fabrication methods are disclosed. In one such method, at least one structure is formed on a substrate which protrudes outwardly from a plane of the substrate. A beam is used to form a layer of material, at least part of which is in direct contact with a semiconductor structure on the substrate, the semiconductor structure comprising at least one nanowire. The beam has a non-zero angle of incidence relative to the normal of the plane of the substrate such that the beam is incident on one side of the protruding structure, thereby preventing a portion of the nanowire in a shadow region adjacent the other side of the protruding structure in the plane of the substrate from being covered with the material.