Biosensor and Method of Manufacturing the Same

Simple SummaryContent extracted from patent full text and abstract with AI.

This invention is a biosensor built around a field-effect transistor (FET) whose semiconductor channel — a nanowire — contains a deliberately engineered nanoscale constriction (narrowing). The constriction, as small as 5–20 nm at its narrowest point and typically V-shaped in cross-section, concentrates current flow and exploits single-trap quantum phenomena to produce measurable two-level digital switching signals in the drain current. When a target molecule binds near the constriction, it alters these switching signals in a highly sensitive way, enabling detection of individual molecules in liquid biological samples. The device is fabricated on silicon-on-insulator wafers using electron-beam lithography and wet chemical etching, making it compatible with scalable semiconductor manufacturing.

Use CasesContent extracted from patent full text and abstract with AI.

• Real-time detection of specific biomolecules (e.g., proteins, DNA, ions) in blood, urine, or other biological fluids for point-of-care diagnostics.
• Monitoring dynamic molecular processes — such as protein conformational changes — at the single-molecule level in pharmaceutical research.
• Measuring pH, ion concentration, and ionic strength changes in electrolyte solutions for environmental or clinical chemistry analysis.
• Integration into lab-on-chip platforms for continuous, label-free biosensing without the need for fluorescent or radioactive markers.
• Development of quantum single-electron/hole tunneling (SET) biosensors operating at room temperature for ultra-sensitive electrochemical measurements.
• CMOS-compatible biosensor arrays for high-throughput screening of drug candidates or pathogen detection in industrial bioprocessing.

BenefitsContent extracted from patent full text and abstract with AI.

• Sensitivity is increased by up to 400% compared to conventional planar FET biosensors, and up to 10× for sub-10 nm constrictions, due to amplified single-trap stochastic switching effects.
• The V-shaped constriction doubles the effective Debye screening length in liquid, enhancing surface-potential detection in electrolyte environments.
• Wet chemical etching of silicon in the ⟨111⟩ crystal direction produces atomically smooth constriction surfaces, reducing carrier scattering and improving charge-carrier mobility toward bulk silicon values.
• The device operates at room temperature without requiring additional gate electrodes to exploit quantum confinement effects, simplifying fabrication and reducing manufacturing cost.
• Two-level signal (random telegraph signal) analysis provides a new time-constant-based readout that yields a 300% sensitivity gain over conventional drain-current-shift methods.
• The transistor characteristics do not drift over time, eliminating the need for periodic recalibration that is required by conventional biosensors.

Technical Classifications (CPCs)

Inventors & Applicants

Patent Abstract

[0001] The invention relates to a biosensor with a field effect transistor as well as a method for producing a field effect transistor for a biosensor. A biosensor (10) comprises a field effect transistor (11) with source (13) and drain (14). The field effect transistor (11) has a conductor structure (17). The conductor structure (17) has a constriction (18). A specially developed biosensor geometry with constriction ensures the amplification of the sensitivity of biosensors through the capture-emission to/from the attachment site.