Sensitivity estimation of biosensor in a tapered cavity MOSHEMT

• Published in: Physica scripta Vol. 99; no. 5; pp. 55017 - 55037
• Main Authors: Dastidar, Ananya, Patra, Tapas Kumar, Mohapatra, Sushanta Kumar, Pradhan, K P, Alodhayb, Abdullah N
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.05.2024
• Subjects: biosensor; estimations; HEMT; sensitivity; tapered
• ISSN: 0031-8949; 1402-4896
• DOI: 10.1088/1402-4896/ad37b0

Abstract The present research provides a comprehensive investigation of the structural modification at the cavity under the gate (CUG) on the metal oxide semiconductor high electron mobility transistor (MOSHEMT)-based biosensor by projecting its basic figures of merit (FOMs). The effect of a tapering dielectric on the sensitivity of the biosensor has not been extensively investigated in many research efforts. Therefore, to account for the larger binding surface, the current study considers a wide range of permittivity of the biomolecules from 1 to 10, using the dielectric modulation technique in the tapered cavity. Various cavities are analysed to enhance the sensitivity. The findings indicate that the presence of biomolecules causes a considerable fluctuation in the drain current, threshold voltage, on-current, off-current, channel potential, and oxide capacitance. It has also been estimated how various fill percentages and charged and neutral biomolecules affect the device’s sensitivity. The tapered dielectric MOSHEMT offered an on-current sensitivity and threshold voltage sensitivity of 1.25 and 0.889 for neutral biomolecule (k = 8) and 0.562 and 2.23 for positively charged biomolecule respectively. Thus, tapering of the oxide does offer better sensitivities that can be exploited for biosensing applications.