Abstract:
Efficient, miniaturized, lightweight, and cost-effective electronic devices are the need
of the moment. The main goal of electronic researchers is to increase the performance
of FETs, which are the building blocks of microelectronics, but the issue of trade-off
between mobility and ION/IOFF is still prevalent in currently used FETs, which
decreases its performance. To overcome this, SWCNTs were used as an active region,
and Self Assembled Monolayer (SAM) was used as a gate dielectric. Three different
SAMs of differing dielectric constant (Octanethiol (OT), Dodecanethiol (DDT),
Benzyl Mercaptan (BMT)) were employed as a gate dielectric in SWCNT-FET. Two
different concentrations of SWCNTs were used. SAMs were grown by immersion
method while SWCNTs were deposited by the drop-casting method. After the
preparation of SWCNT-FET, various analyses were performed using different
characterization tools. Electrical measurements were done by Keithley source meter.
It was observed that CNTFETs with low concentrations had ten times better
properties as compared to high concentration ones. Among SAMs, DDT with low
concentration showed an optimum balance between ION/IOFF ratio and mobility.
Raman and FTIR spectroscopy was used to confirm the successful deposition of
SWCNTs and SAMs in fabricated devices. Analysis of CNTFETs showed that they
performed very well considering SAMs as the only gate dielectric. Devices
performance can be further improved by taking pure semiconducting CNTs as a
channel, and passivation of channel surface with SAMs to avoid oxidation and
contamination from the environment.