Analytical Modeling of a Nanogap-Embedded FET for Application as a Biosensor

作者：Choi Ji Min^*; Han Jin Woo; Choi Sung Jin; Choi Yang Kyu

来源：IEEE Transactions on Electron Devices, 2010, 57(12): 3477-3484.

DOI：10.1109/TED.2010.2076152

• Biotransistor
• Dielectric-modulated field-effect transistor (DMFET)
• field-effect transistor (FET)-type biosensor
• nanogap
• nanogap-embedded FET
• sensitivity
• surface potential
• threshold voltage
• 2-D modeling
• 2-D Poisson equation

An analytical model of a nanogap-embedded field-effect transistor, which is termed here simply as a biotransistor, is developed in this study. A surface potential model is attained by solving a 2-D Poisson equation with approximation of a parabolic potential profile along the channel depth. The analytical threshold voltage is then derived from the surface potential model to comprise the unique feature of the biotransistor, which acts as a biosensor. A shift of the threshold voltage was used as a metric to ascertain the sensitivity after the biomolecule interacts with the biotransistor. Various device parameters were investigated in the developed analytical model. The characteristic trend is supported and verified via a simulation. Hence, the proposed model can provide a useful guideline for the optimal design and fabrication of a biotransistor.

• 出版日期2010-12