Tunnel Junction Molecule Sensor via Dielectric Trenching
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Solution Overview
Problem
Existing methods for manufacturing devices for detecting target molecules, such as those using recognition tunneling, face challenges like damage to metal electrodes during nano-sized opening drilling, which complicates the manufacturing process and increases costs.
Innovation Solution
A method involving depositing electrodes, creating trenches through the dielectric layer to expose the tunnel junction, and using passivating layers to minimize damage and facilitate target molecule detection without the need for drilling through metal electrodes, allowing for easier and more economical mass production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a nano-sized opening is drilled through metal electrodes to enable target molecule detection, then detection capability is achieved, but damage to the metal electrodes occurs leading to electrical shorting
Solution Approach 1:
The patent divides the electrode structure into three distinct layers: a bottom electrode, a dielectric layer, and a top electrode. The tunnel junction is formed between the bottom electrode and the top electrode through the dielectric layer, eliminating the need to drill through the metal electrodes themselves. This segmentation allows the opening to be created only through the dielectric layer, preventing damage to the conductive pathways.
Solution Approach 2:
The dielectric layer serves as an intermediary between the bottom and top electrodes. By forming the tunnel junction through this dielectric layer rather than through the metal electrodes, the patent uses the dielectric as a mediator that enables detection capability while protecting the electrodes from damage and preventing electrical shorting.
2Reliability
If traditional drilling methods are used to create openings through electrode sandwiches, then nanopores are formed for detection, but manufacturing complexity and cost increase
Solution Approach 1:
The manufacturing process is simplified by segmenting the opening creation step to only require drilling through the dielectric layer rather than through the entire electrode sandwich. This reduces the number of drilling steps, eliminates the need for precise alignment through multiple layers, and simplifies the overall manufacturing process while maintaining detection functionality.
Solution Approach 2:
The electrodes are deposited onto the dielectric layer before the opening is created. This preliminary arrangement of the electrode structure eliminates the need for critical alignment steps during the drilling process, as the electrodes are already in their final positions. The opening is then created through the dielectric layer without requiring precise alignment, significantly simplifying manufacturing.
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 minimizes damage during manufacturing, reduces the complexity of critical alignment steps, and enables efficient detection of target molecules by creating a functional tunnel junction without electrical shorting, enhancing the reliability and cost-effectiveness of the devices.
Implementation Method 1
nucleic acid bases are read using the electron tunneling current signals generated as nucleobases pass through a tunnel gap
Implementation Method 2
a readout device constructed from a planar sandwich of a Pd electrode, a layer of dielectric and a top Pd electrode
Data Source
AI summary
Embodiments of the disclosure are directed to a device for molecule sensing. In some embodiments, the device includes a first electrode separated from a second electrode by a dielectric layer. The first electrode comprises a large area electrode and the second electrode comprises a small area electrode. At least one opening (e.g., trench) cut or otherwise created into the dielectric layer exposes a tunnel junction therebetween whereby target molecules in solution can bind across the tunnel junction.