Concave FET Biosensor Structure for Reliable Biomolecule Detection
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Solution Overview
Problem
Biosensors based on semiconductor technology face reliability issues due to sensitivity challenges, particularly in bio-MEMS devices.
Innovation Solution
A semiconductor structure is developed with a biosensor configuration that includes a concave sensing portion capacitively coupled to a field effect transistor (FET), enhancing sensitivity by placing biomolecules closer to the FET for improved detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional biosensor structures are used, then manufacturing is simpler, but sensitivity and reliability are insufficient
Solution Approach 1:
The sensing portion is designed with a concave curvature instead of a flat surface. This curved structure increases the effective surface area for biomolecule binding and enhances the capacitive coupling between the sensing portion and the FET gate, thereby improving sensitivity and reliability without significantly complicating the manufacturing process
Solution Approach 2:
The sensing portion extends in the vertical dimension (thickness direction) rather than only in the planar direction. By forming a concave structure that protrudes toward the FET, the sensing portion creates additional detection volume and strengthens the electric field interaction, improving detection capability while maintaining manufacturing feasibility
2Measurement precision
If sensing portion is placed farther from FET, then manufacturing is easier, but detection sensitivity decreases
Solution Approach 1:
The concave curvature of the sensing portion allows it to be positioned closer to the FET while maintaining manufacturing feasibility. The curved geometry enables stronger capacitive coupling and closer proximity to the FET gate, thereby enhancing detection sensitivity without requiring overly complex manufacturing processes
Solution Approach 2:
The sensing portion's geometric parameters (curvature radius, thickness, position) are optimized to achieve the closest possible placement to the FET while remaining manufacturable. By adjusting these parameters, the design achieves maximum sensitivity improvement without excessive manufacturing difficulty
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 configuration allows for precise and reliable detection of biological targets by varying drain current based on biomolecule binding, improving sensitivity and reliability of biosensor performance.
Implementation Method 1
a first sensing portion (210a) of a sensing film (210) capacitively coupled to the first FET (140a)
Data Source
AI summary
A semiconductor structure includes a sensor and a dielectric layer. The sensor includes a first device and a second device, the first device includes a first field effect transistor (FET) and a first sensing portion of a sensing film coupled to the first FET, the second device includes a second FET and a second sensing portion of the sensing film coupled to the second FET, where the first device and the second device have different functions, and the second sensing portion is flatter than the first sensing portion. The dielectric layer is disposed on the sensing film and includes a sensing well located above the first device and the second device.