Nanowire Field-Effect Sensor With Nano-Network Structure
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Solution Overview
Problem
Conventional nanowire field-effect sensors using silicon-on-insulator substrates are costly and have low integration density, with sensitivity issues due to small detection surface areas and difficulty in large-scale production, and the receptor and target materials are not reusable, leading to high maintenance costs and reduced sensor sensitivity.
Innovation Solution
A nanowire field-effect sensor with a network structure fabricated using a bulk silicon substrate, featuring vertically arranged pins on the sidewalls with a gate insulating layer, a bottom insulating layer to prevent leakage, and a detector material fixed to the nano-network for selective target material reaction, reducing fabrication costs and increasing integration density and sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If silicon-on-insulator substrates are used for nanowire field-effect sensors, then the sensors can be fabricated with controlled electrical properties, but the fabrication cost increases and integration density decreases
Solution Approach 1:
The patent extracts the essential function of electrical property control from the expensive silicon-on-insulator substrate structure and implements it using a simplified bulk silicon substrate with selective insulation layers. This removes the unnecessary complexity of the SOI substrate while retaining the critical electrical control capability through selective oxidation and insulation layer formation at specific regions only.
Solution Approach 2:
The patent replaces the expensive silicon-on-insulator substrate with a cheaper bulk silicon substrate. The bulk substrate serves as a cost-effective alternative that achieves the same electrical control function through simpler fabrication processes, reducing material costs and making the sensor more economically viable for mass production.
2Reliability
If silicon-on-insulator substrates are used for nanowire field-effect sensors, then the sensors can be fabricated with controlled electrical properties, but the integration density decreases
Solution Approach 1:
The patent segments the insulation function to specific regions where it is actually needed, rather than providing blanket insulation across the entire substrate as in SOI structures. By applying insulation layers selectively at source/drain regions and interfaces, the design achieves electrical control while leaving other areas open for higher density integration of multiple sensor elements on the same substrate.
Solution Approach 2:
The patent transitions from the planar insulation approach of SOI substrates to a vertical/dimensional approach using selective oxidation layers and interface engineering in bulk silicon. This dimensional change allows for complex electrical control in three-dimensional space while maintaining substrate compatibility with standard CMOS processes, enabling higher integration density.
3Ease of manufacture
If small nanowire structures are used, then the fabrication process is simplified, but the detection surface area decreases and sensitivity is reduced
Solution Approach 1:
The patent implements a nested hierarchical structure where nanowires are arranged in bundled configurations, with multiple nanowires nested within a common insulation structure. This nesting approach increases the total detection surface area by aggregating multiple nanowire surfaces while maintaining the fabrication simplicity of individual nanowire formation processes, thereby improving sensitivity without complicating manufacturing.
Solution Approach 2:
The patent merges multiple nanowire detection elements into a unified sensor structure with common source/drain regions and shared insulation layers. This combining approach increases the effective detection surface area and sensitivity while reducing the overall fabrication complexity by reusing common structural elements across multiple sensing elements, achieving both goals simultaneously.
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 use of a bulk silicon substrate significantly reduces fabrication costs, enhances integration density, and improves sensor sensitivity by increasing the detection surface area while maintaining structural stability and preventing sensitivity deterioration.
Implementation Method 1
a gate insulating layer formed on a pin vertically arranged on each sidewall of the nano-network
Implementation Method 2
a bottom insulating layer formed between the bulk silicon substrate and the nano-network in such a manner that the bottom portion of each of the source electrode region and the drain electrode region is maintained connected to the bulk silicon substrate and the bottom portion of the nano-network is completely insulated from the bulk silicon substrate
Implementation Method 3
a detector material fixed to the nano-network so as to selectively react with a target material that is externally introduced
Implementation Method 4
When the charged target material reacts with and binds to the receptor material on the detection surface, the electrical conductivity in the channel of the sensor is changed by the charge of the target material
Data Source
AI summary
Disclosed herein is a technology for fabricating a nanowire field-effect sensor, in which a bulk silicon substrate is used so that the fabrication cost of the sensor can be reduced while the integration density of the sensor can be increased. In addition, the nanowire field-effect sensor includes a nano-network having a network structure in which pins are vertically arranged on the sidewalls of the network, respectively, and a gate insulating layer is applied to the pins. Due to this nano-network, the detection area of the sensor can be increased to increase its sensitivity, and the structural stability of the sensor can be ensured.