Silicon Nanowire Biosensor Defect Region Electron Beam
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Solution Overview
Problem
Conventional biosensors face a trade-off between improving transistor performance and sensitivity, as high doping concentration is needed for low contact resistance with metal electrodes but low doping is required for high sensitivity in detecting biomaterials, which affects electron mobility and current flow.
Innovation Solution
A biosensor with a silicon nanowire that includes a defect region formed by electron beam irradiation, allowing for reduced electron mobility in specific areas to enhance sensitivity while maintaining low contact resistance with metal electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the doping concentration of the silicon nanowire is increased to improve electron mobility and lower contact resistance, then transistor performance is improved, but sensitivity of the biosensor decreases because the silicon nanowire cannot operate at low current
Solution Approach 1:
The patent applies local quality by creating a defect region with modified electron mobility characteristics in a specific portion of the silicon nanowire. The defect region is formed by irradiating a predetermined region of the silicon nanowire with an electron beam, causing local changes in the crystal structure that reduce electron mobility in that specific area. This allows the nanowire to operate at low current (improving sensitivity) while maintaining good contact with metal electrodes (maintaining transistor performance) through the non-defect regions that retain higher electron mobility.
2Measurement precision
If the doping concentration is lowered to increase sensitivity and enable low current operation, then sensitivity is improved, but contact resistance against metal electrodes increases
Solution Approach 1:
The patent resolves this contradiction by creating spatially differentiated regions within the silicon nanowire. The defect region has reduced electron mobility that enables low current operation and high sensitivity, while the non-defect regions maintain higher electron mobility that ensures low contact resistance with metal electrodes. This local differentiation allows the nanowire to simultaneously achieve both low contact resistance and high sensitivity without requiring uniform doping concentration changes throughout the entire nanowire.
3Ease of manufacture
If uniform doping concentration is used throughout the silicon nanowire, then manufacturing is simplified, but it is impossible to simultaneously achieve low contact resistance and high sensitivity
Solution Approach 1:
The patent applies preliminary action by first forming the silicon nanowire with uniform doping concentration (maintaining manufacturing simplicity), and then subsequently creating the defect region through electron beam irradiation. This two-step approach allows the nanowire to be manufactured using standard uniform doping processes, and then later modified to create the functional defect region that enables both low contact resistance and high sensitivity. The defect region is formed after the nanowire is already in place, allowing precise localization without requiring complex doping pattern formation.
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 biosensor achieves improved transistor performance and sensitivity by lowering electron mobility in defect regions, enabling effective biomaterial detection with reduced operation current.
Implementation Method 1
irradiating an electron beam to a predetermined region of the silicon nanowire to form a defect region
Data Source
AI summary
Provided are a biosensor with a silicon nanowire and a method of manufacturing the same, and more particularly, a biosensor with a silicon nanowire including a defect region formed by irradiation of an electron beam, and a method of manufacturing the same. The biosensor includes: a silicon substrate; a source region disposed on the silicon substrate; a drain region disposed on the silicon substrate; and a silicon nanowire disposed on the source region and the drain region, and having a defect region formed by irradiation of an electron beam. Therefore, by irradiating a certain region of a high-concentration doped silicon nanowire with an electron beam to lower electron mobility in the certain region, it is possible to maintain a low contact resistance between the silicon nanowire and a metal electrode and to lower operation current of a biomaterial detection part, thereby improving sensitivity of the biosensor.