Label-free biosensor using nanogap embedded dielectric modulated schottky tunneling source impact ionization MOS

• Investigated a novel dielectric modulated schottky tunneling source IMOS bio-sensor
• It offers highly sensitive, label-free electrical detection of bio-molecules.
• Sensitivity can be optimized by varying the length of nanogap.
• TCAD study is deployed to provide physical insight of working mechanism of our device.

In this paper, we have investigated a novel nanogap embedded dielectric modulated schottky tunneling source impact-ionization MOS (DM-STS-IMOS) for highly sensitive, real-time label-free electrical detection of bio-molecules. The current gating mechanism of STS-IMOS is governed by cumulative effect of both impact ionization and source induced tunneling. Both of these mechanisms are synergistically leveraged for pathogenic biomolecule sensors design scheme. Technology computer-aided design (TCAD) simulation study is deployed to provide physical insight into the working mechanism and performance estimation of the proposed sensor. DM-STS-IMOS exhibits enhanced sensitivity and as the operating voltage of DM-STS-IMOS is lower than the conventional IMOS, it has significantly enhanced reliability and higher power efficiency. The length of the nanogap is recognized as a potential parameter to optimize the device sensitivity. It demonstrates dominant dielectric modulation effects, easy recovery mechanism and higher sensitivity even at smaller channel lengths. It can also be exploited in array-based screening and in-vivo bio-species diagnostics.

Fig. The proposed dielectric modulated schottky tunneling source impact-ionization MOS (DM-STS-IMOS).A novel nanogap embedded dielectric modulated schottky tunneling source impact-ionization MOS (DM-STS-IMOS) for highly sensitive, label-free electrical detection of bio-molecules.Figure optionsDownload as PowerPoint slide