Field-Effect Transistors (FETs) are those which can carry current along a channel whose resistance can be controlled by a transverse electric field. FETs can highly integrate themselves and also have low-cost potential. They have gained popularity due to biosensing applications like protein, virus and DNA detection, pH sensing, etc. The threshold voltage of biomolecules changes when they bind themselves to the chemically modified dielectric surface of the gate. This result is the formation of a signal that can be measured. Even though FETs have been subjected to continuous research, the progress in the development of BioFET devices has not reached the potential necessary to turn it into a successful product.
Recently IMEC (Interuniversity Microelectronics Centre), an international R&D organization, has unveiled small silicon by the name finFET that functions as a biosensor. It comes with ultra-small dimensions of 13 nm fin width and 50 nm gate lengths. The biosensor is fabricated with CMOS – compatible process flow in IMEC’s 300 mm cleanroom. It is a significant development in the Biosensors Market as the new BioFETs may have the ability to integrate themselves into high-throughput, cost-effective detection tools. IMEC envisions volume manufacturing of BioFETs and them working in thousand parallel to each other. However, for now, the detection limit is to tens of molecules a day, and so IMEC targets those BioFETs which are highly accurate by sensing single DNA molecules.
IMEC investigated how a superior generation of CMOS FET devices (finFETs) with three-dimensional short length gates will be able to improve the responsive nature of BioFETs and open new applications. These finFETS are highly advantageous in terms of high integration and parallelization. However, as of yet, very little has been was known about their potential as a BioFET.
The organization has demonstrated a strong signal for DNA hybridization and the ability to detect tens of DNA molecules present on the surface of nano-scale finFETs. As per the team's experiments and stimulation, it has been predicted that single-molecule detection with an SNR (Signal to noise ratio) > five may be possible with -70 nm FinFETs.
As humankind is obsessed with faster computation and data access, the semiconductor industry has developed so much that one can integrate a huge number of nano-scale devices into highly intricate systems. This can be done with just a few square millimeters of silicon with the help of mass manufacturing that can easily establish atomic precision. IMEC is further working to enhance these capabilities to build better communication devices and enable chip-based tools to reveal things about biology that have been inaccessible till now.