TY - GEN
T1 - Fe/Ge catalyzed carbon nanotube growth on HfO2 for nano-sensor applications
AU - Uchino, T.
AU - Ayre, G. N.
AU - Smith, D. C.
AU - Hutchison, J. L.
AU - De Groot, C. H.
AU - Ashburn, P.
PY - 2009
Y1 - 2009
N2 - A carbon nanotube (CNT) growth process on HfO2 is reported for the first time for application in nano-sensors, The process uses a combination of Ge nanoparticles and ferric nitrate dispersion and achieves an increase in CNT density from 0.15 to 6.2 μm length/μm2 compared with the use of ferric nitrate dispersion alone. The growth process is validated by the fabrication of back-gate CNT field-effect transistors (CNTFETs) using AI source/drain (S/D) contacts and a H2 anneal at 400°C. The transistors exhibit p-FET behavior with an Ion/Ioff ratio of 105 and a steep sub-threshold slope of 130 mV/dec. These results are rather surprising, as earlier research in the literature on CNTFETs with AI S/D electrodes showed n-FET behavior. The p-FET behavior is shown to be due to the H2 anneal, which we ascribe to the smaller electron affinity of hydrogenised CNTs. Measurements of the temperature dependence of the drain current show low Schottky barrier height AI S/D contacts after a H2 anneal, which tends to confirm this explanation.
AB - A carbon nanotube (CNT) growth process on HfO2 is reported for the first time for application in nano-sensors, The process uses a combination of Ge nanoparticles and ferric nitrate dispersion and achieves an increase in CNT density from 0.15 to 6.2 μm length/μm2 compared with the use of ferric nitrate dispersion alone. The growth process is validated by the fabrication of back-gate CNT field-effect transistors (CNTFETs) using AI source/drain (S/D) contacts and a H2 anneal at 400°C. The transistors exhibit p-FET behavior with an Ion/Ioff ratio of 105 and a steep sub-threshold slope of 130 mV/dec. These results are rather surprising, as earlier research in the literature on CNTFETs with AI S/D electrodes showed n-FET behavior. The p-FET behavior is shown to be due to the H2 anneal, which we ascribe to the smaller electron affinity of hydrogenised CNTs. Measurements of the temperature dependence of the drain current show low Schottky barrier height AI S/D contacts after a H2 anneal, which tends to confirm this explanation.
UR - http://www.scopus.com/inward/record.url?scp=72849133276&partnerID=8YFLogxK
U2 - 10.1109/ESSDERC.2009.5331539
DO - 10.1109/ESSDERC.2009.5331539
M3 - Conference contribution
AN - SCOPUS:72849133276
SN - 9781424443536
T3 - ESSDERC 2009 - Proceedings of the 39th European Solid-State Device Research Conference
SP - 197
EP - 200
BT - ESSDERC 2009 - Proceedings of the 39th European Solid-State Device Research Conference
T2 - 39th European Solid-State Device Research Conference, ESSDERC 2009
Y2 - 14 September 2009 through 18 September 2009
ER -