Dielectric-Modulated Impact-Ionization MOS Transistor as a Label-Free Biosensor

In this letter, we propose a dielectric-modulated impact-ionization MOS (DIMOS) transistor-based sensor for application in label-free detection of biomolecules. Numerous reports exist on the experimental demonstration of nanogap-embedded field effect transistor-based biosensors, but an impact-ionization MOS (I-MOS)-based biosensor has not been reported previously. The concept of a dielectric-modulated I-MOS-based biosensor is presented in this letter based on technology computer-aided design simulation study. The results show a high sensitivity to the presence of biomolecules even at small channel lengths. In addition, a low variability of the sensitivity to the charges on the biomolecule is observed. The high sensitivity, dominance of dielectric-modulation effects, and operation at even small channel lengths make the DIMOS biosensor a promising alternative for CMOS-based sensor applications.