Paul van Gerven
17 December 2020

Imec has presented the smallest silicon FinFET that functions as a biosensor. Fabricated in a CMOS-compatible process, the Leuven research hub envisions volume manufacturing and integration into high-throughput, cost-effective detection tools, with 10,000s of these ‘bioFETs’ working in parallel. With a detection limit of tens of molecules today, Imec ultimately targets highly accurate bioFETs sensing single DNA molecules.

Due to their high integration and low-cost potential, field-effect transistors (FETs) have gained a lot of interest for biosensing applications such as DNA, protein and virus detection or pH sensing. When biomolecules bind to the chemically modified dielectric surface of the gate, its threshold voltage changes, resulting in a measurable signal.

Artist impression of Imec’s bioFET with DNA molecules (red) attached to it. Source and drain are pictured in gold.

Despite continuous research progress in this field, ‘traditional’ FET devices haven’t yet been turned into successful sensing products. Imec has explored whether FinFETs, with their three-dimensional gate structures, can improve the sensitivity of bioFETs and open up new applications. FinFETS have advantages because of high integration and parallelization but very little was understood about their potential as a bioFET.

With its modified FinFET devices with lengths down to 50 nanometers, Imec has demonstrated robust detection of tens of DNA molecules on the surface of nanoscale FinFETs. Based on experiments and simulations, the research institute predicts single-molecule detection with a signal to noise ratio (SNR) > 5 to be possible with sub-70 nm FinFETs.

“We’re leveraging our capabilities to integrate a very large number of nanoscale devices into complex systems not only to build better computers or communication devices but also to enable chip-based tools for the life sciences that are game-changing in their ability to reveal details about biology that were hitherto inaccessible,” commented Peter Peumans, CTO of health technologies at Imec.