Sub-30nm In2O5Sn gate electrode recessed channel MOSFET: A biosensor for early stage diagnostics

This paper presents a technology computer-aided design (TCAD) analysis of an ultrasensitive In2O5Sn gate (transparent gate) recessed channel (TGRC) metal-oxide-semiconductor field effect transistor (MOSFET) as a biosensor for early-stage disease diagnostics. The key parameters such as sensitivity, switching ratio, and threshold voltage shift have been compared with the conventional MOSFET. For immobilizing the protein molecules, a cavity has been embedded in the gate insulator region due to which gate capacitance changes owing to the accumulation of protein molecules which reflects the deviation in threshold voltage. Higher sensitivity (1.542) is achieved for protein at a very low drain bias (0.2 V) in comparison to streptavidin and APTES ((3-Aminopropyl) triethoxysilane). Moreover, the cavity gap variation (from 8 to 15 nm) and oxide thickness limitation has also been observed for the device as a biosensor. All the results pave way for early detection techniques of protein-related diseases such as Alzheimer's diseases, ovarian cancer and coronary artery disease with the existing complementary metal oxide semiconductor (CMOS) technology.