Analysis of mobility in ultra-long individual single walled carbon nanotubes fets before and after dna addition
Soh, Alvin Yang Zhi
Date of Issue2014
School of Mechanical and Aerospace Engineering
Carbon nanotubes (CNTs) are special material that exhibits extraordinary properties that are ideal for nanotechnology, optics, electronic. One such example is sensors that are used for biological and chemical systems. For single wall carbon nanotubes (SWCNT), the size can range from as small as diameter of 1-2nm and length of 0.2um to 5um. They exhibit excellent mechanical, electrical and thermal properties for their size ratio. Any minor changes of the nano particle will alter the properties of the CNT. CNT which is used in FET replaces the commonly used silicon that is in the MOSFET, they have exceptional electrical properties, strong bonding, good conductivity and used less power than conventional FET thus they are widely used in replace of silicon in FET. CNT based Biosensor is widely used as they can provide accurate and faster response due to their size and properties. SWCNT were grown using chemical vapour deposition method, they will produce short or long channel CNT-FET. They have excellent attributes such as good current on/off ratio, low threshold leakage current, sub threshold swing and threshold voltage and good mobility in room temperature. The high mobility CNTs has a large surface to volume ratio sensitive to biomolecules with comparable dimensions like (DNA). The effective physical and the conventional field-effect mobility of a CNTFET were measured, then computed to get a ratio. The mobility were measured using a MOSFET in the strong and near-threshold region by changing the gate and drain voltages before and after DNA binding. In the strong inversion region, the mobility ratio did not varies too much for either setup, whereas in the near-threshold region, the ratio of the effective and the conventional field effect mobility increases after DNA binding.
Final Year Project (FYP)
Nanyang Technological University