Gate coupling and carrier distribution in silicon nanowire/nanoribbon transistors operated in electrolyte
2011 (English)In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 29, no 1, 011022- p.Article in journal (Refereed) Published
The transfer characteristics of back-gate silicon nanowire/nanoribbon (NW/NR) transistors measured in electrolyte exhibit a significantly higher on-current and a steeper subthreshold behavior than measured in air. Simulation results show that the gate capacitance for a NW/NR of a trapezoidal cross-section immersed in water is significantly higher than that exposed to air. Electrostatics simulations further show that for NWs/NRs with small widths, carriers are mainly accumulated at the two side-edges when they are immersed in water. Even the top surface of the NWs/NRs sees more accumulated carriers than the bottom one does; the latter is in fact located closest to the back-gate. These observations suggest that the interface properties at the side-edges and the top surface are crucial for NW/NR transistors to achieve high sensitivity when performing real-time sensing experiments in electrolyte. Finally, the sensitivity of back-gate NW/NR field-effect transistors to charge changes in electrolyte is found to have a weak dependence on the NW/NR width when the doping concentration is below 10(17) cm(-3). For higher NW/NR doping concentrations, narrower NWs/NRs are more sensitive.
Place, publisher, year, edition, pages
2011. Vol. 29, no 1, 011022- p.
Engineering and Technology
Research subject Engineering Science with specialization in Electronics
IdentifiersURN: urn:nbn:se:uu:diva-149590DOI: 10.1116/1.3528215ISI: 000286648300024OAI: oai:DiVA.org:uu-149590DiVA: diva2:405124